ה֚וּא מְרוֹמִ֣ים יִשְׁכֹּ֔ן מְצָד֥וֹת סְלָעִ֖ים מִשְׂגַּבּ֑וֹ לַחְמ֣וֹ נִתָּ֔ן מֵימָ֖יו נֶאֱמָנִֽים׃
He shall dwell on high; His place of defence shall be the munitions of rocks; His bread shall be given, his waters shall be sure.
Rashi on Isaiah
his bread shall be given He will not seek bread, for it will be supplied to him from heaven.
Rashi on Isaiah
his water sure The source of his water will not fail. I.e., his seed will become great, and all his wants will be supplied.