John Gill Commentary Isaiah 7:11

"Ask thee a sign of Jehovah thy God; ask it either in the depth, or in the height above." — Isaiah 7:11 (ASV)

Ask you a sign of the Lord your God For though Ahaz was a wicked man, yet the Lord was his God, as he was the God of the people of Israel in general, as a nation; and knowing his unbelief and diffidence of his word to him, offers to confirm it by a sign or miracle:

ask it either in the depth, or in the height above, in earth, or in heaven: so the Targum,

"ask that a miracle may be done for you upon earth, or that a sign may be shown you in heaven;"

either that the earth might gape and open its mouth, as in the days of Moses; or that the sun might stand still, as in the times of Joshua; or that a dead man might be raised out of the depth of the earth; or that there might be some strange appearances in the heavens.