The Prince Mastema

The Book of Jubilees Reu and Serug, 1 (cf. Gen. xi.20, 21). Rise of war and bloodshed and eating of blood and idolatry, 2-7. Nachor and Terah, 8-14 (cf. Gen. xi.22-30). Abram's knowledge of YHVH and wonderful deeds, 15-24.

[Chapter 11]

1. And in the thirty-fifth jubilee, in the third week, in the first year thereof, Reu took to himself a wife, and her name was 'Ôrâ, the daughter of 'Ûr, the son of Kesed, and she bare him a son, and he called his name Sêrôh, in the seventh year of this week in this jubilee.
2. And the sons of Noah began to war on each other, to take captive and to slay each other, and to shed the blood of men on the earth, and to eat blood, and to build strong cities, and walls, and towers, and individuals (began) to exalt themselves above the nation, and to found the beginnings of kingdoms, and to go to war people against people, and nation against nation, and city against city, and all (began) to do evil, and to acquire arms, and to teach their sons war, and they began to capture cities, and to sell male and female slaves.
3. And 'Ûr, the son of Kesed, built the city of 'Ara of the Chaldees, and called its name after his own name and the name of his father. And they made for themselves molten images, and they worshipped each the idol, the molten image which they had made for themselves, and they began to make graven images and unclean simulacra, and malignant spirits assisted and seduced (them) into committing transgression and uncleanness.
4. And the prince Mastêmâ exerted himself to do all this, and he sent forth other spirits, those which were put under his hand, to do all manner of wrong and sin, and all manner of transgression, to corrupt and destroy, and to shed blood upon the earth.
5. For this reason he called the name of Sêrôh, Serug, for every one turned to do all manner of sin and transgression.
6. And he grew up, and dwelt in Ur of the Chaldees, near to the father of his wife's mother, and he worshipped idols, and he took to himself a wife in the thirty-sixth jubilee, in the fifth week, in the first year thereof,  and her name was Melka, the daughter of Kaber, the daughter of his father's brother.
7. And she bare him Nahor, in the first year of this week, and he grew and dwelt in Ur of the Chaldees, and his father taught him the researches of the Chaldees to divine and augur, according to the signs of heaven.
8. And in the thirty-seventh jubilee in the sixth week, in the first year thereof,  he took to himself a wife, and her name was 'Ijaska, the daughter of Nestag of the Chaldees.
9. And she bare him Terah in the seventh year of this week.
10. And the prince Mastêmâ sent ravens and birds to devour the seed which was sown in the land, in order to destroy the land, and rob the children of men of their labours. Before they could plough in the seed, the ravens picked (it) from the surface of the ground.
11. And for this reason he called his name Terah because the ravens and the birds reduced them to destitution and devoured their seed.
12. And the years began to be barren, owing to the birds, and they devoured all the fruit of the trees from the trees: it was only with great effort that they could save a little of all the fruit of the earth in their days.
13. And in this thirty-ninth jubilee, in the second week in the first year,  Terah took to himself a wife, and her name was 'Edna, the daughter of 'Abram, the daughter of his father's sister. And in the seventh year of this week  she bare him a son, and he called his name Abram, by the name of the father of his mother;
14. for he had died before his daughter had conceived a son.
15. And the child began to understand the errors of the earth that all went astray after graven images and after uncleanness, and his father taught him writing, and he was two weeks of years old,  and he separated himself from his father, that he might not worship idols with him.
16. And he began to pray to the Creator of all things that He might save him from the errors of the children of men, and that his portion should not fall into error after uncleanness and vileness.
17. And the seed time came for the sowing of seed upon the land, and they all went forth together to protect their seed against the ravens, and Abram went forth with those that went, and the child was a lad of fourteen years.
18. And a cloud of ravens came to devour the seed, and Abram ran to meet them before they settled on the ground, and cried to them before they settled on the ground to devour the seed, and said, ' Descend not: return to the place whence ye came,' and they proceeded to turn back.
19. And he caused the clouds of ravens to turn back that day seventy times, and of all the ravens throughout all the land where Abram was there settled there not so much as one.
20. And all who were with him throughout all the land saw him cry out, and all the ravens turn back, and his name became great in all the land of the Chaldees.
21. And there came to him this year all those that wished to sow, and he went with them until the time of sowing ceased: and they sowed their land, and that year they brought enough grain home and eat and were satisfied.
22. And in the first year of the fifth week  Abram taught those who made implements for oxen, the artificers in wood, and they made a vessel above the ground, facing the frame of the plough, in order to put the seed thereon, and the seed fell down therefrom upon the share of the plough, and was hidden in the earth, and they no longer feared the ravens.
23. And after this manner they made (vessels) above the ground on all the frames of the ploughs, and they sowed and tilled all the land, according as Abram commanded them, and they no longer feared the birds.

The Book of Jubilees Moses returns from Midian to Egypt. Mastêmâ seeks to slay him on the way, 1-3. The ten plagues, 4-11. Yisrayl goes forth out of Egypt: the destruction of the Egyptians on the Red Sea, 12-19. (Cf. Exod. ii.15; iv.19, 24; vii. seqq.)


Chapter 48

1. And in the sixth year of the third week of the forty-ninth jubilee thou didst depart and dwell <in the land of Midian>, five weeks and one year. And thou didst return into Egypt in the second week in the second year in the fiftieth jubilee.
2. And thou thyself knowest what He spake unto thee on  Mount Sinai, and what prince Mastêmâ desired to do with thee when thou wast returning into Egypt <on the way when thou didst meet him at the lodging-place>.
3. Did he not with all his power seek to slay thee and deliver the Egyptians out of thy hand when he saw that thou wast sent to execute judgment and vengeance on the Egyptians?
4. And I delivered thee out of his hand, and thou didst perform the signs and wonders which thou wast sent to perform in Egypt against Pharaoh, and against all his house, and against his servants and his people.
5. And YHVH executed a great vengeance on them for Yisrayl's sake, and smote them through (the plagues of) blood and frogs, lice and dog-flies, and malignant boils breaking forth in blains; and their cattle by death; and by hail-stones, thereby He destroyed everything that grew for them; and by locusts which devoured the residue which had been left by the hail, and by darkness; and <by the death> of the first-born of men and animals, and on all their idols The Most High took vengeance and burned them with fire.
6. And everything was sent through thy hand, that thou shouldst declare (these things) before they were done, and thou didst speak with the king of Egypt before all his servants and before his people.
7. And everything took place according to thy words; ten great and terrible judgments came on the land of Egypt that thou mightest execute vengeance on it for Yisrayl.
8. And YHVH did everything for Yisrayl's sake, and according to His covenant, which he had ordained with Abraham that He would take vengeance on them as they had brought them by force into bondage.
9. And the prince Mastêmâ stood up against thee, and sought to cast thee into the hands of Pharaoh, and he helped the Egyptian sorcerers,
10. and they stood up and wrought before thee the evils indeed we permitted them to work, but the remedies we did not allow to be wrought by their hands.
11. And YHVH smote them with malignant ulcers, and they were not able to stand, for we destroyed them so that they could not perform a single sign.
12. And notwithstanding all (these) signs and wonders the prince Mastêmâ was not put to shame because he took courage and cried to the Egyptians to pursue after thee with all the powers of the Egyptians, with their chariots, and with their horses, and with all the hosts of the peoples of Egypt.
13. And I stood between the Egyptians and Yisrayl, and we delivered Yisrayl out of his hand, and out of the hand of his people, and YHVH brought them through the midst of the sea as if it were dry land.
14. And all the peoples whom he brought to pursue after Yisrayl, YHVH our Father cast them into the midst of the sea, into the depths of the abyss beneath the children of Yisrayl, even as the people of Egypt had cast their children into the river He took vengeance on 1,000,000 of them, and one thousand strong and energetic men were destroyed on account of one suckling of the children of thy people which they had thrown into the river.
15. And on the fourteenth day and on the fifteenth and on the sixteenth and on the seventeenth and on the eighteenth the prince Mastêmâ was bound and imprisoned behind the children of Yisrayl that he might not accuse them.
16. And on the nineteenth we let them loose that they might help the Egyptians and pursue the children of Yisrayl.
17. And he hardened their hearts and made them stubborn, and the device was devised YHVH our Father that He might smite the Egyptians and cast them into the sea.
18. And on the fourteenth we bound him that he might not accuse the children of Yisrayl on the day when they asked the Egyptians for vessels and garments, vessels of silver, and vessels of gold, and vessels of bronze, in order to despoil the Egyptians in return for the bondage in which they had forced them to serve.
19. And we did not lead forth the children of Yisrayl from Egypt empty handed.

Book of Jubilees According to the book of Jubilees, Mastema "Hostility" is the chief of the demons engendered by the fallen Watchers/Angels with women, perhaps one of those same demons.

His actions and name indicate he is Satan, the 'Adversary', but much more the Satan who appears in the book of Job with a function to fulfill under God than the Satan of later tradition who is the uttermost enemy of God. Beliar, mentioned twice in Jubilees, is likely to be identical with Mastema in this work.

When God is ready to destroy all these demons after the flood and Noah prays that his descendants be released from their attacks, Mastema intervenes, beseeching God to allow him to retain and control one tenth of these demons in order to exercise his authority because they are "intended to corrupt and lead astray before my judgement because the evil of the sons of men is great". So Mastema is the tester of humans with God's permission.

Mastema sends a plague of birds onto the land in the days of Terah.

Later, Mastema counsels God to test Abraham (Jubilees 17:15-16) just as Satan in the book of Job wants permission to test Job. As Abraham prepares to sacrifice his son Isaac, Mastema stands in God's presence. On his deathbed Isaac promises that the spirits of Mastema will have no power to turn Jacob or his descendants away from Yahweh.

The strange account in Exodus 4.24 where Yahweh meets Moses by the way and tries to kill him is retold in a way that attributes the attack to Mastema instead (Jubilees 48:1-3). It is claimed that Mastema aided the Egyptian priests that opposed Moses. Mastema is also said to have been chained while the Israelites left Egypt but then let go to encourage the Egyptians to chase after the Israelites and so come to their doom in the Red Sea.

On the other hand, the deaths of the firstborn of the Egyptians are attributed to "all the powers of Mastema".