Gen 21:9

21:9 Sarah saw. From her experience with Hagar (ch. 16) Sarah perceived the significance of Ishmael’s disdain for Isaac and his threat to her son’s inheritance.

laughing. The Hebrew root means “to laugh,” but the form here signifies “to laugh at” or “make sport of” (text note). The son of the slave woman persecuted the son of the free (Gal. 4:29).