Charles Ellicott Commentary Isaiah 22:21

"and I will cloth him with thy robe, and strengthen him with thy girdle, and I will commit thy government into his hand; and he shall be a father to the inhabitants of Jerusalem, and to the house of Judah." — Isaiah 22:21 (ASV)

I will clothe him with your robe ... —The words point to an actual transfer of the robe and girdle which were Shebna’s insignia of office. There was to be, in this case, a literal investiture.

He shall be a father ... —The words were, perhaps, an official title given to the king’s vizier or chamberlain. (Compare to 2 Kings 5:13.) Here, however, the words indicate that the idea of the title should be fulfilled, and that the government of Eliakim should be, in the truest sense, paternal.