John Gills Exposition of the Bible Commentary - Genesis 21:9
And Sarah saw the son of Hagar the Egyptian ,.... That is, Ishmael, who is not expressed by name, but described by being a son of Hagar, a servant of Sarah's, and an Egyptian woman; all which seems to be observed by way of slight, both to Hagar and her son: which she had born unto Abraham ; not unto Sarah, as she proposed to herself, when she gave her maid to Abraham, Genesis 16:2 . This son of Abraham she saw mocking ; either at the entertainment made at the weaning of Isaac; or... read more
Matthew Henry's Complete Commentary - Genesis 21:9-13
The casting out of Ishmael is here considered of, and resolved on. I. Ishmael himself gave the occasion by some affronts he gave to Isaac his little brother, some think on the day that Abraham made the feast for joy that Isaac was safely weaned, which the Jews say was not till he was three years old, others say five. Sarah herself was an eye-witness of the abuse: she saw the son of the Egyptian mocking (Gen. 21:9), mocking Isaac, no doubt, for it is said, with reference to this (Gal. 4:29),... read more