Charles Ellicott Commentary 2 Kings 1:4

"Now therefore thus saith Jehovah, Thou shalt not come down from the bed whither thou art gone up, but shalt surely die. And Elijah departed." — 2 Kings 1:4 (ASV)

Now therefore — for this act of faithlessness, and to prove by the event that there is a God in Israel, whose oracle is unerring. (Compare to 1 Kings 18:24 and following).

Thus says. — Or, has said. After these words the prophetic announcement comes in rather abruptly. Perhaps the verse has been abridged by the compiler, and in the original account from which he drew, the words of 2 Kings 1:6 may have followed here, Go, return to the king ... Ekron.

And Elijah departed. — On the Lord’s errand. The Septuagint adds, and said to them, or told them, which is perhaps due to a copyist’s eye having wandered to the words “to him,” or “to them,” in the next verse (Thenius).