John Gills Exposition of the Bible Commentary - Genesis 21:5
And Abraham was an hundred years old when son Isaac was born unto him. So that this was years after his departure from Haran, and coming into the land of Canaan, for then he was seventy five years of age, Genesis 12:4 ; and this exactly agrees with the account of Demetrius, as related by Polyhistor, an Heathen writer F15 Apud Euseb. Praepar. Evangel. l. 9. c. 21. p. 425. , who makes Isaac to be born just twenty five years from Abraham's coming into the land of Canaan, and who must be... read more
John Gills Exposition of the Bible Commentary - Genesis 21:4
And Abraham circumcised his son Isaac, being eight days old as , God had commanded him. Genesis 17:12 , and was the first that we read of that was circumcised on that day, according to the divine precept, which Abraham strictly observed; for though this was the son of the promise, and of his old age, for whom he had the most affectionate regard, yet he administered this bloody ordinance on him; nor did he defer it beyond the time, and was himself the operator, as it seems; all which... read more