7 “Blessed is he whom You have chosen, and hast taken to You”. Who is he that is chosen by Him and taken to Him? Was any one chosen by our Saviour Jesus Christ, or was Himself after the flesh, because He is man, chosen and taken to Him?...Or has not rather Christ Himself taken to Him some blessed one, and the same whom He has taken to Him is not spoken of in the plural number but in the singular? For one man He has taken to Him, because unity He has taken to Him. Schisms He has not taken to Him, heresies He has not taken to Him: a multitude they have made of themselves, there is not one to be taken to Him.
But they that abide in the bond of Christ and are the members of Him, make in a manner one man, of whom says the Apostle, “Until we all arrive at the acknowledging of the Son of God, unto a perfect man, unto the measure of the age of the fullness of Christ.” Therefore one man is taken to Him, to which the Head is Christ; because “the Head of the man is Christ.” The same is that blessed man that “has not departed in the counsel of ungodly men,” and the like things which there are spoken of: the same is He that is taken to Him.
He is not without us, in His own members we are, under one Head we are governed, by one Spirit we all live, one fatherland we all long for....And to us He will give what? “He shall inhabit,” he says, “in Your courts.” Jerusalem, that is, to which they sing that begin to go forth from Babylon: “He shall inhabit in Your courts: we shall be filled with the good things of Your House.” What are the good things of the House of God? Brethren, let us set before ourselves some rich house, with what numerous good things it is crowded, how abundantly it is furnished, how many vessels there are there of gold and also of silver; how great an establishment of servants, how many horses and animals, in a word, how much the house itself delights us with pictures, marble, ceilings, pillars, recesses, chambers:— all such things are indeed objects of desire, but still they are of the confusion of Babylon.
Cut off all such longings, O citizen of Jerusalem, cut them off; if you will return, let not captivity delight you. But have you already begun to go forth? Do not look back, do not loiter on the road. Still there are not wanting foes to recommend you captivity and sojourning: no longer let there prevail against you the discourses of ungodly men. For the House of God long thou, and for the good things of that House long thou: but do not long for such things as you are wont to long for either in your house, or in the house of your neighbour, or in the house of your patron....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)