Reference for Genesis 35:7

את שבעת המזבחות — “Seven altars I have set in order” is not written here, but “THE SEVEN ALTARS”. He said to Him: The ancestors of these people together built before Thee seven altars, but I alone have built altars equal to all of them. — Abraham built four: (Genesis 12:7) “And he built there an altar to the Lord who had appeared to him”; (Genesis 12:8) “And he removed thence unto the mount… [and he built there an altar]; (Genesis 13:18) “And Abraham moved his tent … [and built there an altar]”; and one he built on Mount Moriah (Genesis 22:9). Isaac built one: (Genesis 26:25) “And he built there an altar”. Jacob built two, one at Shechem and one at Bethel (Genesis 33:20 and Numbers 25:7);