Why did Bil'am instruct Balak to stand by his Olah?
Seforno: In order to have the right intentions whilst each part of the sacrifice was being burned on the Mizbe'ach. 1
Why did Bil'am insert the word "Ulai"?
Rashi: Because Hashem was not accustomed to appearing to him by day. 1
Seforno: Because he was not on the level of Moshe, who, once he was established, was donkeyured of Hashem's attention at any time. 2 And he figured that perhaps Hashem would come to meet him, like He came to meet Moshe when he first became a prophet. 3
What does "Vayeilech Shefi" mean?
Rashi and Targum Onkelos: It means 'He went alone'.
Rashbam: It means 'He went limping'. 1