Albert Barnes Commentary 1 Samuel 7:3-5

"And Samuel spake unto all the house of Israel, saying, If ye do return unto Jehovah with all your heart, then put away the foreign gods and the Ashtaroth from among you, and direct your hearts unto Jehovah, and serve him only; and he will deliver you out of the hand of the Philistines. Then the children of Israel did put away the Baalim and the Ashtaroth, and served Jehovah only. And Samuel said, Gather all Israel to Mizpah, and I will pray for you unto Jehovah." — 1 Samuel 7:3-5 (ASV)

Compare the marginal references. Twenty years of Samuel’s life had passed since he was last mentioned (1 Samuel 4:1). He now appears in the threefold character of prophet, judge, and the acknowledged leader of the whole people. His words were an answer to a profession of repentance by Israel, the practical proof of which would be to put away all their false gods (compare the note on Judges 6:10).

Will pray for you... So Moses prayed for the people at Rephidim (Exodus 17:11–12) and for Miriam (Numbers 12:13); so Elijah prayed at Carmel (1 Kings 18:36, 42); so Ezra prayed at the evening sacrifice (Ezra 9:5); so the High Priest prayed for the house of Israel on the Day of Atonement; and so our Lord Jesus Christ ever lives at God’s right hand to make intercession for us.