Why did Balak think that this time Bil'am would succeed?
Seforno: He thought that perhaps the section of the people that Bil'am would now see would be more susceptible to curse than the previous one.
What is the meaning of "Vekaboso li mi'Sham"?
Rashi: It means Perhaps 1 "You will curse them for me there".
Rashi: It is a statement following the word "Ulai", not a command.
After Bil'am categorically informed Balak that Hashem blessed Yisrael and would not curse them, why did Balak persist with his request that Bil'am curse them?
Ramban (on Pasuk 24): Having accepted the fact that Yisrael were blessed and were destined to capture Eretz Cana'an, he hoped that he would still manage to deal them a blow 1 - as did Amalek; or that he would be able to recapture the lands that had previously belonged to Mo'av, and that Yisrael had captured from Sichon. 2