Genesis 21:9
8 The child grew and was weaned. Abraham prepared a great feast on the day that Isaac was weaned. 9 But Sarah noticed the son of Hagar the Egyptian—the son whom Hagar had borne to Abraham—mocking. 10 So she said to Abraham, “Banish that slave woman and her son, for the son of that slave woman will not be an heir along with my son Isaac!”
LXX Genesis 21:9
8 And the child grew and was weaned, and Abraam made a great banquet on the day his son Isaak was weaned. 9 But when Sarra saw the son of Hagar the Egyptian, who had been born to Abraam, playing with her son Isaak, 10 then she said to Abraam, “Cast out this slave-girl and her son; for the son of this slave-girl shall not inherit together with my son Isaak.”
Jubilees 17:4
3 And he remembered the words which He had spoken to him on the day on which Lot had parted from him, and he rejoiced because the Lord had given him seed upon the earth to inherit the earth, and he blessed with all his mouth the Creator of all things. 4 And Sarah saw Ishmael playing and dancing, and Abraham rejoicing with great joy, and she became jealous of Ishmael and said to Abraham, 'Cast out this bondwoman and her son; for the son of this bondwoman will not be heir with my son, Isaac.'
Notes and References
"... Jubilees 17:4a reads: “Sarah saw Ishmael playing and dancing.” apart from the rendering of 'the son of Hagar the Egyptian, whom she had borne to Abraham,' with the proper name 'Ishmael,' there is an addition at the end: 'and dancing.' The Latin text of Jubilees instead reads 'with Isaac.' It is possible that the Hebrew קחצמ ('playing') is the basis for the first verb in the Ethiopic text of Jubilees 17:9a. The second verb was a corruption ... Charles thus considered the Masoretic text of Genesis 21:9a defective, the Septuagint of Genesis 21:9a representing the more original text. According to Vander Kam, it could be true that the combination of a preposition and a name was misread at some point as a verb. At the same time, the Latin version of Jubilees may have been influenced by the Septuagint tradition later on in the textual transmission of Jubilees. Finally, it may not be irrelevant that the Greek verb παίζω could mean both 'to play' and 'to dance.' perhaps one should also add that the proper name Isaac and the verb 'to play' have the same root ..."
van Ruiten, J. Abraham in the Book of Jubilees: The Rewriting of Genesis 11:26-25:10 in the Book of Jubilees 11:14-23:8 (p. 201) Brill, 2012