In 22:29 Bil’am responds to his donkey by saying if he had a sword he would kill the donkey. Rashi mentions that in the eyes of the ministers accompanying him it was an embarrassment that he had to threaten the donkey with physical violence, while he was on the way to supposedly destroy the Jews by using his sharp tongue. After all, why would he need a sword to kill the donkey, why not just say something that will cut short the donkeys life?
What is going on here? Why would they expect Bil’am to present a verbal attack on the pathetic donkey rather than a physical attack, which would clearly be considered normal?
In the original decision to hire Bil’ams services, Balak expressed the knowledge that he had no physical power to beat the Jewish nation and he knew he needed to beat the Jews at their own game – by verbal powers. He specifically pursued and hired Bil’am because Bil’am was unique among the nations of the world, whose strength normally lies in the physical realm, in that Bil’ams strength was similar to the strength of the Jews, by using his mouth.
The raison d’être of Bil’am was to gain advantage by curses and blessings. He could use any lowly servant to attack with physical violence. Now he sees Bil’am getting frustrated over a confrontation with a donkey (!) and he threatens the donkey with physical violence. When a person gets frustrated lie that, he generally lashes out, and usually will attack with what is second nature to him, in Bil’ams case he should have automatically cursed the donkey and felled it in its tracks. But he did not. He threatened it with violence.
That made the ministers think maybe we are bringing back a fraud to Balak. They were embarrassed they spent so much time and effort pursuing the services of somebody who clearly did not have the powers (or at least the level of powers) he claimed to have.
The gemora even says in many places one of the ways to know a person is to view him in his state of anger. At that time he reacts with a natural reaction and by watching him at that time you will see if he is really in control of himself, and if not you will see what comes naturally to him. The ministers witnessed Bil’am in his state of anger and frustration and they saw that he was not all he claimed to be..