Bilam (Balaam) is not a member of God’s covenant and was a foreigner to them, although he was from the land of Aram, the ancestral homeland of Abraham. Yet, God saw fit to give him His words, His visions and to Bilam and use Bilam as God’s instrument among the people.
Israel didn’t credit God with the victory over the Amorites and other blessings, namely the coming of manna each morning to feed the people. God sent death amid the people — and the cure in the image of the instrument of that death. There’s an important prophecy about the work of Messiah Yeshua in this account, something Yeshua didn’t want Nicodemus to miss from his studies of the Torah.