15 Then Balak again sent princes, more numerous and more1 honorable than they.
16 And they came to Balaam and said to him, “Thus says Balak the son of Zippor: ‘Please let nothing hinder you from coming to me;
17 for I will certainly ahonor you greatly, and I will do whatever you say to me. bTherefore please come, curse this people for me.’ ”
18 Then Balaam answered and said to the servants of Balak, a“Though Balak were to give me his house full of silver and gold, bI could not go beyond the word of the Lord my God, to do less or more.
19 Now therefore, please, you also astay here tonight, that I may know what more the Lord will say to me.”
20aAnd God came to Balaam at night and said to him, “If the men come to call you, rise and go with them; but bonly the word which I speak to you—that you shall do.”
In essence, Balak is saying, "I can't fight Israel with the sword, so I have to fight them with evil spirits. I have to whittle them down somehow so that my puny army can defeat them."