en_tn_condensed/2ch/06/15.md

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

"you who have done what you promised your servant David my father"

you spoke with your mouth

"you yourself spoke"

and have fulfilled it with your hand

"and, by your power, have fulfilled what you said" or "and by your power have done what you said"

as it is today

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