John Gill

May be able to comprehend with all saints,.... This is the end of their being rooted and grounded in love, that they, together with the rest of the saints interested in it, might have a larger and more comprehensive view of what is the breadth, and length, and depth, and height; not of God himself, who is incomprehensible by finite minds, and is not to be found out to perfection; see Job 11:7 but either of the great mystery of salvation, particularly the mystery of the calling of the Gentiles mentioned in the beginning of the chapter; or of the spiritual building, the church, the dimensions of which are given, Rev 21:15 or rather of the love of God, which in its length reaches from one eternity to another; in its breadth to all the elect, in all ages, places, and nations; and in its depth to saints in the lowest state of life; and in its height to bring them to an exalted state in glory.