Albert Barnes on Acts 21:5

Had accomplished those days. When those days were passed.

They all brought us on our way. They attended us. Acts 15:3; Rom 15:24; 1Cor 16:6,11; 3Jn 1:6. This was an expression of tender attachment, and of a deep interest in the welfare of Paul and his fellow-travellers.

We kneeled down. Acts 20:36.

On the shore. Any place may be proper for prayer. Jn 4:21, also Jn 4:22-24. God is everywhere, and can as easily hear the prayer of the humble on the sea-shore as in the most magnificent temple. This is an instance, as well as that in Acts 20:36, where the apostle evidently prayed with the church without a form of prayer. No man can believe that he thus poured forth the desires of his heart at parting, and commended them to God, in a prescribed form of words. Besides that, there is not the least evidence that such a form was then used in the Christian church: scenes like this show more clearly than abstract arguments could do, that such a form was not needed, and would not be used. Paul and his fellow Christians, on the sand of the sea-shore, would pour forth the gushing emotions of their souls in language such as their circumstances would suggest, and such as such a scene would demand. And it is presumed to be impossible that any man can read this narrative in a dispassionate manner without believing that they offered an extempore prayer.

(*) "accomplished" "completed" (+) "brought" "conducted" (a) "kneeled" Acts 20:36