May be able to comprehend with all saints what is the breadth, and length, and depth, and height. — It has been asked, Of what? Various answers have been given; but as St. Paul has obviously of set purpose omitted all definition, leaving the phrase incomplete in absolute generality, no answer can be perfectly satisfactory. The early fathers delighted to refer it to the cross, and to trace in the four dimensions of the cross a symbol of this four-fold extension of the love of God in Christ. The clause following, “to know the love of Christ,” though partly explanatory of this, hardly seems to be identical or co-extensive with it. The knowledge there described is a part — perhaps the chief part, but not the whole — of the comprehension here prayed for. If anything is to be supplied, it should probably be “of the mystery” — i.e., of the whole mystery on which St. Paul had been dwelling, including the predestination, the redemption, the call and union of Jews and Gentiles. The prayer is that we may know it every way, in every direction in which the soul can go forth towards God.
It may be noted that comprehension is placed after love, just as in Philippians 1:9, “I pray that your love may abound (that is, overflow) in knowledge and in all judgment.” The spiritual order of revelation differs from that of the “wisdom of the world.” It has first faith, next love, and finally knowledge, because its object is a person, not an abstract principle. That knowledge must, even here, “grow from more to more;” but St. Paul’s prayer can never be perfectly realised till we “know even as we are known.”