Why does the Torah write "va'Yikar" in connection with Bil'am, and "va'Yikra" in connection with Moshe?
Rashi and Ramban: Refer to Vayikra, 1:1:5:1. 1 (When Hashem appeared to Bil'am, his hair stood on end, a trembling seized him, he was gripped with terror, his whole demeanor changed and he fell on his face to the ground - Ramban).
Refer to Vayikra, 1:1:5:2.
The Ramban adds that it says "va'Yavo Elokim el Bil'am" (22:2), and by others who were not prophets - such as Avimelech - in Bereishis 20:3, and Lavan - in Bereishis 31:24 - See Ramban.
Why, on this occasion, did Hashem appear to Bil'am by day?
Rashi and Ramban: In honor of Yisrael.
What was Bil'am referring to when he mentioned 'the seven Mizb'chos'?
Why did he tell Hashem about the Mizb'chos that he had built?
Ramban (on Pasuk 1): He did so in the form of a prayer, in the hope that Hashem would accept his sacrifices favorably and grant him his request. 1
But He did not, as stated in the next Pasuk.
Why did Bil'am conclude "Va'a'al Par va'Ayil ba'Mizbe'ach"?
Rashi: He was boasting that, whereas Avraham brought only a ram on the Mizbe'ach, he brought a bull as well (on each Mizbe'ach)!