1 Kings 18:15

And Elijah said, As the LORD of hosts liveth, before whom I stand, I will surely shew myself unto him to day.

Elijah solemnly swore to Obadiah that he would surely show himself to Ahab that same day. The oath was made by appealing to the living Lord of hosts, before whom he stood. By that appeal he declared that he served in God's presence, was accountable to God, and called God as witness to his promise.

The oath answered Obadiah's fear that Elijah would disappear and leave him to be killed for delivering the message. It assured him that Elijah would keep his word despite the danger. It assured him that the dangerous errand would not be in vain and would not be a futile risk. It assured him that Elijah would remain where he could be found.

Acting as God's messenger, Elijah did not go to Ahab himself but sent word for Ahab to come and meet him. The promise belongs to Elijah's faithful stand for God against Israel's idolatry on Mount Carmel. The rain that followed was testimony to the blessings awaiting Israel.

Afterward, fear of Jezebel's threats in weakness and weariness made him flee. This failure of faith cut short the work he had begun, so God appointed another prophet to succeed him. Even so, God honored Elijah's faithful service by not letting him die alone in the wilderness or descend to the grave. He was taken by angels into God's presence in heaven.