There is no nation ... - This is expressed in the style of Oriental hyperbole. What Obadiah means is: "there is no nation nor kingdom, of those over which he has influence, whither the king has not sent." He could scarcely, for example, have exacted an oath from such countries as Egypt or Syria of Damascus. But Ahab may have been powerful enough to expect an oath from the neighboring Hittite, Moabite, and Edomite tribes, perhaps even from Ethbaal his father-in-law, and the kings of Hamath and Arpad.

There is no nation or kingdom - He had sent through all his own states and to the neighboring governments to find out the prophet, as he knew, from his own declaration, that both rain and drought were to be the effect of his prayers. Had he found him, he no doubt intended to oblige him to procure rain, or punish him for having brought on this drought.

He took an oath - Ahab must have had considerable power and authority among the neighboring nations to require and exact this, and Elijah must have kept himself very secret to have shunned such an extensive and minute search.

As the Lord thy God liveth,.... Which is the form of an oath he thought fit to make, to ascertain the truth of what he was about to say:

there is no nation or kingdom, whither my lord hath not sent to seek thee; which is either an hyperbolical expression, signifying he had sought for him in many places, and in every place he could think of; or it must be understood either of the ten tribes, which were as so many nations and kingdoms as they had been; or were more in the times of the Canaanites; or of the nations round about, that were in alliance with or tributary to the king of Israel:

and when they said, he is not there, he took an oath of the kingdom and nation that they found thee not; which he might exact of his own subjects, but could not of other nations, unless they were free to it of themselves; or he might take it of their ambassadors or merchants that came into his land, of whom he inquired, and adjured them to tell him the truth.

As the LORD thy God liveth, there is no nation or kingdom, whither my lord hath not sent to seek thee: and when they said, He is not there; he took an oath of the kingdom and nation, that they found thee not.

18:10 No nation - Near his own, where he could in reason think that Elijah had hid himself. It does not appear, that Ahab sought him, in order to put him to death: but rather in hopes of prevailing upon him, to pray for the removal of the drought.

18:1-16 The severest judgments, of themselves, will not humble or change the hearts of sinners; nothing, except the blood of Jesus Christ, can atone for the guilt of sin; nothing, except the sanctifying Spirit of God, can purge away its pollution. The priests and the Levites were gone to Judah and Jerusalem, 2Ch 11:13,14, but instead of them God raised up prophets, who read and expounded the word. They probably were from the schools of the prophets, first set up by Samuel. They had not the spirit of prophecy as Elijah, but taught the people to keep close to the God of Israel. These Jezebel sought to destroy. The few that escaped death were forced to hide themselves. God has his remnant among all sorts, high and low; and that faith, fear, and love of his name, which are the fruits of the Holy Spirit, will be accepted through the Redeemer. See how wonderfully God raises up friends for his ministers and people, for their shelter in difficult times. Bread and water were now scarce, yet Obadiah will find enough for God's prophets, to keep them alive. Ahab's care was not to lose all the beasts; but he took no care about his soul, not to lose that. He took pains to seek grass, but none to seek the favour of God; fencing against the effect, but not inquiring how to remove the cause. But it bodes well with a people, when God calls his ministers to stand forth, and show themselves. And we may the better endure the bread of affliction, while our eyes see our teachers.