וְאֵ֛לֶּה תּוֹלְדֹ֥ת יִצְחָ֖ק בֶּן־אַבְרָהָ֑ם אַבְרָהָ֖ם הוֹלִ֥יד אֶת־יִצְחָֽק׃
And these are the generations of Isaac, Abraham’s son: Abraham begot Isaac.
Targum Jonathan on Genesis
These are the generations of Izhak bar Abraham. And because the appearance of Izhak resembled the appearance of Abraham, the sons of men said, In truth Abraham begat Izhak.