If it had not been the LORD who was on our side, now may Israel say;
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Augustine of Hippo
2 ...Certain members indeed of that body of which we also are, which can sing in truth, have gone before us. And this the holy Martyrs have sung: for they have already escaped, and are with Christ in joy about to receive at last incorruptible bodies, the very same which were at first corruptible, wherein they have suffered pains; of the same there will be made for them ornaments of righteousness. Therefore whether they in reality, or we in hope, joining our affections with their crowns, and longing for such a life as we have not here, and shall never gain unless we have longed for it here, let us all sing together, and say, "If the Lord Himself had not been in us." ...
1. Ye already well know, dearest brethren, that a "Song of Degrees," is a song of our ascent: and that this ascent is not effected by the feet of the body, but by the affections of the heart. This we have repeatedly reminded you of: and we need not repeat it too often, that there may be room for saying what hath not yet been said. This Psalm, therefore, which ye have now heard sung for you, is inscribed, "A Song of Degrees." This is its title. They sing therefore while ascending: and sometimes as it were one man singeth, sometimes as it were many; because many are one, since Christ is One, and in Christ the members of Christ constitute one with Christ, and the Head of all these members is in heaven. But although the body toileth on earth, it is not cut off from its Head; for the Head looketh down from above, and regardeth the body. ...Whether therefore one or many sing; many men are one man, because it is unity; and Christ, as we have said, is One, and all Christians are members of Chr...
Canticle. Hebrew, with some Latin copies add, "of David "(Calmet) who might write it after being delivered from some danger. It may also be applicable to the martyrs, and to all who have been freed from temptation. (Berthier)
The captives might compose it in thanksgiving for the leave to return, (Calmet) or when they had been delivered from the assaults of the neighbouring nations. (Origen) (Calmet)