John 8:56

“Your father Abraham rejoiced to see my day, and he saw it and was glad'.

Abraham had been told by God that ‘by you all the families of the earth will be blessed' and that ‘kings would be born of him' (Genesis 12:3; Genesis 17:6; compare Genesis 22:18), and as he looked forward to kings being born from him he might well have associated the coming time of blessing with the coming of a righteous future king descended from him, one who would rule nations as he ruled his family tribe (compare Genesis 49:10). How else could the nations of the world be blessed through him? Abraham thus rejoiced in the great day when God and the world would be at one through his descendants and looked forward to that day of God. This came out especially when at last the chosen son, through whom the promises would begin fulfilment, was born, for laughter was continually associated with that birth, even in the very name Isaac itself (meaning ‘laughter'). Abraham rejoiced at the birth of Isaac for he rejoiced at him as the sign of the fulfilment of the promises in the future.

There was also a Rabbinic tradition that when God made His covenant with Abraham He showed him the day of the Messiah. Genesis Rabbah 44:25ff states that Rabbi Akiba, in a debate with Rabbi Johanan ben Zakkai, held that Abraham had been shown not this world only but the world to come, which would include the days of the Messiah.

But this statement of Jesus, taken over-literally, produced derision.