When I shall make the land of Egypt desolate,.... The cities being demolished, the inhabitants destroyed with the sword, or carried captive:
and the country shall be destitute of that whereof it was full; men and cattle, corn and other fruits of the earth, wealth and riches, pomp and grandeur:
when I shall smite all them that dwell therein; with the sword of the Chaldeans:
then shall they know that I am the Lord for God is known in the perfections of his nature, omnipotence, omniscience, holiness, justice, c. by the judgments he executes for this is not to be understood of a spiritual knowledge of him, but of a terrible conviction of the truth of his being and attributes, by the awful dispensations of his providence.