Psalms 106:28

“They joined themselves also unto Baal-peor - They joined in their devotions, or, they shared in the rites of idolatrous worship. This occurred when they were in the regions of Moab, and on the very borders of the promised land. Numbers 25:0. Many other instances of a similar kind are passed over by the psalmist, and this seems to have been selected because of its special aggravation, and to show the general character of the nation. Even after their long-continued enjoyment of the favor and protection of God - after he had conducted them safely through the wilderness - after he had brought them to the very border of the land of Canaan, and all his promises were about to be fulfilled, they…”

“Joined - They had communion with him, as God's people have with God in acts of his worship. Psalms 106:31”

“106:28-39 Israel’s idolatry outside of the land came with them into the land. Their nature did not change; they continued to provoke the Lord to anger by their actions. 106:28 the worship of Baal at Peor: See Num 25:3; Deut 4:3.”

“joined: Num 25:1-3, Num 25:5, Num 31:16; Deu 4:3, Deu 32:17; Jos 22:17; Hos 9:10; Rev 2:14 of the dead: The word maithim signifies dead men; for the idols of the heathen were generally men - warriors, kings, or lawgivers - who had been deified after their death; though many of them had been execrated during their life. Psa 115:4-8; Jer 10:8-10; Co1 10:19, Co1 10:20 Psalms 106:29”