וַיֹּ֗אמֶר בָּר֤וּךְ יְהוָה֙ אֱלֹהֵ֣י יִשְׂרָאֵ֔ל אֲשֶׁר֙ דִּבֶּ֣ר בְּפִ֔יו אֵ֖ת דָּוִ֣יד אָבִ֑י וּבְיָדָ֥יו מִלֵּ֖א לֵאמֹֽר׃
And he said: ‘Blessed be the LORD, the God of Israel, who spoke with His mouth unto David my father, and hath with His hands fulfilled it, saying:
Rashi on II Chronicles
Who spoke with His mouth that He would give him a son who would build Him a House.