Matthew Poole and continuators on 2 Kings 16:18

18 And the covert for the sabbath that they had built in the house, and the kings entry without , turned he from the house of the LORD, for the king of Assyria .

The form and use whereof is now unknown. It is generally understood of some Building, or Covert, either that where the Priests after their weekly course was ended, abode until the next course came, and relieved them; which was done upon the Sabbath day, see 2 Kings 11. 5, 7. or that in which the Guard, or Watchmen of the Temple, kept their station; or that under which the King used to sit to hear God's Word, and see the Sacrifices; which is called, the covert of the Sabbath, because the chief times in which the King used it for those ends, was the Weekly Sabbath, and other solemn days of Feasting, or Fasting (which all come under the name of Sabbaths in the Old Testament), upon which the King used more certainly, and solemnly, to present himself before the Lord, than at other times.

By which the King used to go from his Palace to the Temple; see on, 1 Kings 10. 5, 12.

i. e. That he might ingratiate himself with the King of Assyria, by his publick contempt and rejection of that Religion which had been the onely Partition-Wall between the Kings of Iudah, and other Kings; and which possibly the present King of Assyria, did vehemently dislike and hate; and therefore required these things from Ahaz.