Targum zu Bereschit 22:1

And it was after these things that Izhak and Ishmael contended; and Ishmael said, It is right that I should inherit what is the father's because I am his firstborn son. And Izhak said, It is right that I should inherit what is the father's, because I am the son of Sarah his wife, and thou art the son of Hagar the handmaid of my mother. Ishmael answered and said, I am more righteous than thou, because I was circumcised at thirteen years; and if it had been my will to hinder, they should not have delivered me to be circumcised; but thou wast circumcised a child eight days; if thou hadst had knowledge, perhaps they could not have delivered thee to be circumcised. Izhak responded and said, Behold now, today I am thirty and six years old; and if the Holy One, blessed be He, were to require all my members, I would not delay. These words were heard before the Lord of the world, and the Word of the Lord at once tried Abraham, and said to him, Abraham! And he said, Behold me.

And it was after these things that the Lord tried Abraham with the tenth trial, and said to him, Abraham! And he said, Behold me.