A Commentary on the Psalms by Saint Bruno:
"How lovely is Your dwelling place. My soul longs to enter the courts of the Lord," the heavenly Jerusalem, the city of God.
The psalmist tells us why he longs to enter the courts of the Lord: "Blessed are those who dwell in Your house," the heavenly Jerusalem, O Lord, God of all heavenly powers, my King and my God. It is as if he said: "Who would not wish to enter Your courts, since You are God, the Creator, Lord of powers, King, and since all who dwell in Your house are blessed?" Court and house are the same thing to him. When he says "blessed" he means that they are possessed of as great a blessedness as it is possible to conceive. So it follows that they are blessed because "they will praise You with loving devotion, world without end," that is "for eternity." They would not praise Him for eternity, if they were not blessed for eternity.
No man can attain this blessedness of himself, even though he has hope, faith and charity. But "that man is blessed" whom You help to climb the ladder to blessedness which he has set up in his heart. That is to say: the only man that can be said to be likely to attain blessedness is he who, once he has set his heart on climbing to blessedness by the many steps of virtue and good works, receives help from Your grace. No man can, of himself, ascend to such heights; as the Lord says, "No one has ascended into heaven except the Son of man Who is in heaven."
I say that "he has set up the ladder" because he is living now in this vale of tears of tribulation, compared with that other life which may be called a mountain and full of joy in comparison with this present one.
Since the Lord said, "Blessed are they whose strength is in You," one might ask, "Will God's help be forthcoming?" To which we reply: "Help from God is there for the blessed." For the Lawgiver, Christ Himself Who gave us the law, gives and will go on giving His blessings, the innumerable gifts of grace, by which He blesses His own. This means He will raise them up to blessedness. As they make the ascent, they will, by His blessings, mount from strenght to strength. In time to come, in the heavenly Sion, Christ Himself, the God of gods, will deify those who are His own. To put it another way: the God of gods, the divine Trinity, will be seen in a spiritual way among those who dwell in Sion; or, yet again, by the light of the intellect they will see among themselves God, Whom here they cannot see; for God will be All in all.