Psalms 116:7

The psalmist is talking to himself, and that is the first thing to notice.

Return to your rest, my soul. It is not addressed to God. It is a man giving instructions to his own interior, which is one of the recurring moves in the Psalms and one of the most practical things in the book. There is a version of the inner life in which you are simply a spectator of your own moods. The psalms do not accept this. They talk back.

The word return matters too. It assumes he had rest, left it, and can go back. Rest is treated as a place with an address rather than a state you either possess or don't. He has been away — the earlier verses say where, and it was somewhere close to death — and he is now directing himself home.

And the ground he gives himself is entirely backward-looking: Yahweh has dealt bountifully with you. Not will deal. Has. He argues himself into rest using evidence he already has, which is the only kind available at the point when you most need the argument.

That is a technique, not a temperament. When the mind will not settle, it is not usually short of feeling; it is short of a case. This verse makes one, in eleven words, out of things that have already happened.