Albert Barnes Commentary 1 Samuel 3:18

"And Samuel told him every whit, and hid nothing from him. And he said, It is Jehovah: let him do what seemeth him good." — 1 Samuel 3:18 (ASV)

It is the Lord — Compare the devout submission of Aaron (Leviticus 10:3) and of Hezekiah (2 Kings 20:19). And for the highest conceivable submission to the will of God, compare Luke 22:42.