Matthew Poole and continuators on 1 Kings 18:10

10 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 .

To wit, near to his own, where he could in reason think that Elijah had hid himself. Nothing is more frequent than to understand general expressions with such limitations.

Not that he could force other Kingdoms to take an Oath, but that by his persuasions he prevailed with the chief persons in several Kingdoms for his satisfaction to Swear that they did not know of Elijah's being among them. Which was not hard for him to obtain. For Ahab was a great Prince, and had a great interest among the Neighbouring Kings. The King of Tyre was his Father-in-law; the King of Moab Tributary to him; Iehoshaphat, his Friend and Relation, to whom the King of Edom was Tributary. We read also of all the kings of Arabia, and of all the Kings of the Hittites, and of Syria, 1 King. 10. 15, 29. which as they corresponded with Solomon, so how far they might be Allied to, or Confederate with Ahab, we know not; nor what Articles or Agreements were between him and them, among which this might be one, That they should deliver up to one another all their fugitive or banished Subjects upon demand; which might give sufficient ground for his desire or expectation of this Oath. Quest. How then could Elijah lye hid in the House of the Widow of Sarepta? Ans. That might easily be, either, because she her self, or at least others, did not know particularly who he was; or, because she used all possible care to conceal him, her Conscience and Interest both obliging her so to do; or because God secured him there.