Parashat Balak - Numbers 22:2-25:9

If we were to read Parashat Balak in isolation, we would have a pretty high regard for the prophet Balaam. When Balak hires him for the task of cursing Israel, Balaam tells him flat out that he cannot go beyond what the God of Israel tells him. Indeed, each time he offers up his sacrifices and opens his mouth to speak over the Children of Israel, blessings burst forth from his mouth, rather than cursing. And at the end of the parashah he simply leaves Balak and returns home. 

But there must have been something else going on, because in Numbers 31:8 Balaam is killed by the Israelites in their battle against Midian. Not only that, but the rest of the Scriptures paint Balaam as a very wicked person. The Talmud describes him as being blind in one eye and lame in one foot (b.Sanhedrin 105a). But yet he had the insight and persistence to nearly destroy Israel. What did he do that was so horrible and how was he able to accomplish it? Parashat Mattot (Numbers 30:2–32:42) gives us insight into his deeds as it speaks of the Midianite women that Israel had taken captive:

Behold, these, on Balaam's advice, caused the people of Israel to act treacherously against the LORD in the incident of Peor, and so the plague came among the congregation of the LORD. (Numbers 31:16)

But what treachery did Balaam devise against the Israelites and why?