Rashi on Numbers 23:4/רש"י על במדבר כ״ג:ד׳

1ויקר AND [GOD] HAPPENED TO MEET [BALAAM] — This is an expression ordinarily used to denote events of a casual character, an expression for something shameful, an expression for an unclean happening (קרי). It is as much as to say: with reluctance and in a contemptuous manner. And on this occasion He revealed Himself to him by day, only to show how dear Israel was to Him (cf. Genesis Rabbah 52:5; Rashi on Leviticus 1:1).

2את 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 Genesis 35:7);

3ואעל פר ואיל במזבח AND I HAVE OFFERED UPON EVERY ALTAR A BULLOCK AND A RAM — “but Abraham”, said he, “offered only a single ram” (cf. Midrash Tanchuma, Balak 11, Midrash Tanchuma, Tzav 1).