Our father, Isaac

I'm a little behind in my daf yomi, but I did find this interesting piece of Aggada (Shabbat 89b). Usually Isaac is kind of a bland character, but here he plays a role not unlike that of Rachel in the midrash.

R. Samuel b. Nakhmani also said in R. Yonathan's name: What is meant by, For thou art our father, though Abraham knoweth is not, and Israel doth not acknowledge us: thou, O Lord, art our father; our redeemer from everlasting is thy name?
In the future to come the Holy One, blessed be He, will say to Abraham. ‘Thy children have sinned against Me.’ He shall answer Him, ‘Sovereign of the Universe! Let them be wiped out for the sanctification of Thy Name.’ Then shall He say, ‘I will say this to Jacob, who experienced the pain of bringing up children: peradventure he will supplicate mercy for them. ‘So He will say to him, ‘Thy children have sinned.’ He [too] shall answer Him, ‘Sovereign of the Universe! Let them be wiped out for the sanctification of Thy Name.’ He shall retort, ‘There is no reason in old men, and no counsel in children!’ Then shall he say to Isaac, ‘Thy children have sinned against me.’ But he shall answer Him, ‘Sovereign of the Universe! Are they my children and not Thy children. When they gave precedence to "we will do" over "we will hearken" before Thee, Thou calledst them, Israel my son, my firstborn:11 now they are my sons, not Thy sons! Moreover, how much have they sinned? How many are the years of man? Seventy. Subtract twenty, for which Thou dost not punish, [and] there remain fifty. Subtract twenty-five which comprise the nights, [and] there remain twenty-five. Subtract twelve and a half of prayer, eating, and Nature's calls, [and] there remain twelve and a half. If Thou wilt bear all, ‘tis well; if not, half be upon me and half upon Thee. And shouldst Thou say, they must all be upon me, lo! I offered myself up before Thee [as a sacrifice]!’ [Thereupon] they shall commence and say, ‘For thou [i.e., Isaac] art our father.’ Then shall Isaac say to them, ‘Instead of praising me, praise the Holy One, blessed be He,’ and Isaac shall show them the Holy One, blessed be He, with their own eyes. Immediately they shall lift up their eyes on high and exclaim, ‘Thou, O Lord, art our father; our redeemer from everlasting is thy name.’