John Gill Commentary 1 Chronicles 18:2

"And he smote Moab; and the Moabites became servants to David, and brought tribute." — 1 Chronicles 18:2 (ASV)

1 Chronicles 18:18

And he brought the ram for the burnt offering
One of the two he was ordered to take, (Leviticus 8:2)

and Aaron and his sons laid their hands on the head of the ram ;
as they had done before on the head of the bullock, see (Leviticus 8:14) their right hands, as the Targum of Jonathan, and that at the same time; not first Aaron and then his sons, as a famous grammarian, Aben Ezra makes mention of, thought; but, as he himself says, they laid them on together.