וַיֹּ֣אמֶר שְׁלֹמֹ֗ה אַתָּ֨ה עָשִׂ֜יתָ עִם־עַבְדְּךָ֙ דָוִ֣ד אָבִי֮ חֶ֣סֶד גָּדוֹל֒ כַּאֲשֶׁר֩ הָלַ֨ךְ לְפָנֶ֜יךָ בֶּאֱמֶ֧ת וּבִצְדָקָ֛ה וּבְיִשְׁרַ֥ת לֵבָ֖ב עִמָּ֑ךְ וַתִּשְׁמָר־ל֗וֹ אֶת־הַחֶ֤סֶד הַגָּדוֹל֙ הַזֶּ֔ה וַתִּתֶּן־ל֥וֹ בֵ֛ן יֹשֵׁ֥ב עַל־כִּסְא֖וֹ כַּיּ֥וֹם הַזֶּֽה׃
And Solomon said: ‘Thou hast shown unto Thy servant David my father great kindness, according as he walked before Thee in truth, and in righteousness, and in uprightness of heart with Thee; and Thou hast kept for him this great kindness, that Thou hast given him a son to sit on his throne, as it is this day.
Rashi on I Kings
You preserved for him. An expression of authenticating His words as in, “And Adonoy, your God will keep for you, etc.”9Devarim 7:12. Here too You have preserved for him the kindness, You have authenticated Your words to fulfill to him the kindness which You had promised him through Noson the prophet.