John Gill Commentary Ezekiel 20:42

"And ye shall know that I am Jehovah, when I shall bring you into the land of Israel, into the country which I sware to give unto your fathers." — Ezekiel 20:42 (ASV)

And you shall know that I am the Lord The one only Jehovah, that keeps covenant; performs promises; is faithful to his word; is kind, gracious, and merciful, as well as mighty and powerful; and all this they shall experimentally know, and publicly own and acknowledge:

when I shall bring you into the land of Israel; which will be the Lord's doing; his hand and his power will be signally seen in it; this is one of the places in prophecy, which clearly asserts that the Jews, when converted, shall be brought into their own land again: into the country for which I lifted up my hand, to give it to your fathers; that is, which he swore he would give to them.