"... 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 מצחק ('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 ..."