What is the breadth, &c. It is not expressed to what must be referred these metaphorical words of breadth, length, &c. Some expound them of the charity which in our hearts we ought to have for one another; others, of the love which Christ shewed towards mankind, in coming to redeem all. (Witham)

What, &c. This thought seems borrowed from Job xi: “Peradventure thou wilt comprehend the steps of God, and wilt find out the Almighty perfectly.” The inspired writer then shews us how the Almighty is incomprehensible; for, says he, “God is higher than the heavens; and what wilt thou do? he is deeper than hell; and how wilt thou know? The measure of him is longer than the earth, and broader than the sea.” The apostle, alluding to these words, prays that the Ephesians may have faith and charity sufficient to enable them to comprehend all that is comprehensible of God; as St. Dionysius explains it. But we are not hence to conclude, that there exists such a thing as dimension or size with regard to God, for he is a pure Spirit: but these expressions are merely metaphorical. For by breadth we are to understand his virtue and wisdom, which extend over all his creatures: (Ecclesiasticus i.) “he poured out wisdom upon all his works.” By length is meant his eternal duration: (Psalm ci.) “but thou, O Lord, remainest for ever.” By height we are taught the infinite superiority of his nature over ours: (Psalm cxii.) “The Lord is high above all nations.” And by depth we are shewn the incomprehensibility of his wisdom: (Ecclesiastes) “Wisdom is a great depth; who shall find it out?” Hence it appears that the end of faith and charity is, that we may arrive at a perfect faith; which may know, as far as it is intelligible, the greatness of his wisdom, his eternal duration, &c. (St. Thomas Aquinas, in Eph.)