RobH_en_tn/2ch/06/15.md

you who have kept with your servant David my father, what you promised him

"you who have kept your promise to your servant David my father." To keep a promise is an idiom that means to do what one has promised. Alternate translation: "you who have done what you promised your servant David my father" (See: rc://en/ta/man/translate/figs-idiom)

you spoke with your mouth

The phrase "with your mouth" may emphasize that God himself spoke. It was not someone else who made the promise. Alternate translation: "you yourself spoke"

and have fulfilled it with your hand

The hand is a metonym for the power of the hand. Alternate translation: "and, by your power, have fulfilled what you said" or "and by your power have done what you said" (See: rc://en/ta/man/translate/figs-metonymy)

as it is today

This refers to the day when Solomon was saying this prayer.