Adam Clarke on Isaiah 22:15

Go - unto Shebna - The following prophecy concerning Shebna seems to have very little relation to the foregoing, except that it might have been delivered about the same time; and Shebna might be a principal person among those whose luxury and profaneness is severely reprehended by the prophet in the conclusion of that prophecy, Isa 22:11-14.

Shebna the scribe, mentioned in the history of Hezekiah, chap. 36, seems to have been a different person from this Shebna, the treasurer or steward of the household, to whom this prophecy relates. The Eliakim here mentioned was probably the person who, at the time of Sennacherib's invasion, was actually treasurer, the son of Hilkiah. If so, this prophecy was delivered, as the preceding, (which makes the former part of the chapter), plainly was, some time before the invasion of Sennacherib. As to the rest, history affords us no information. "And say unto him" - Here are two words lost out of the text, which are supplied by two of Dr. Kennicott's MSS., one ancient, which read ואמרת אליו veamarta elaiv, and thou shalt say unto him; by the Septuagint, και ειπον αυτῳ, and in the same manner by all the ancient versions. It is to be observed that this passage is merely historical, and does not admit of that sort of ellipsis by which in the poetical parts a person is frequently introduced speaking, without the usual notice, that what follows was delivered by him.