פירוש על מלכים א 8:15

Who spoke with His mouth. That He would grant him a son who would build the Beis [Hamikdosh].¹³“With His mouth,” refers to the “voice” of prophecy which was given through Noson, the prophet, and repeated directly to Dovid. See II Shmuel 7:12-17.

And fulfilled it with His hand. He has fulfilled His word with His good power.¹⁴The literal meaning of ובידו מלא is, “and fulfilled with His hand.” Here it refers to God’s omnipotence, that He alone is able to fulfill any promise He makes, the hand symbolizing strength.—Radak