Ps 90:1

“When the great David heard and understood this, he [David] said to him "who dwells in the shelter of the most High; He will overshadow you with his shoulders," which is the same as being behind God (for the shoulder is on the back of the body). Concerning himself David says, "My soul clings close to you, your right hand supports me." You see how Psalms agree with the history. For as the one says that the right hand is a help to the person who has joined himself close behind God, so the other says that the hand touches the person who waits in the rock on the divine voice and prays that he might follow behind.”

“He then who so imitates Christ as to endure all the troubles of this world, with his hopes set upon God, that he falls into no snare, is broken down by no panic fears, he it is "who dwells under the defence of the Most High, who shall abide under the protection of God" [Psalm 91:1], in the words with which the Psalm, which you have heard and sung, begins. You will recognise the words, so well known, in which the devil tempted our Lord, when we come to them. "He shall say unto the Lord, You are my taker up, and my refuge: my God" [Psalm 91:2]. Who speaks thus to the Lord? "He who dwells under the defence of the Most High:" not under his own defence. Who is this? He dwells under the defence of the Most High, who is not proud, like those who ate, that they might become as Gods, and lost the immortality in which they were made. For they chose to dwell under a defence of their own, not under that of the Most High: thus they listened to the suggestions of the serpent, [Genesis 3:5] and despised the precept of God: and discovered at last that what God threatened, not what the devil promised, had come to pass in them.”

“"When the fullness of time had come, God sent his Son, made from a woman, made under the law." People are upset by "made from a woman," because we confess that he was born of a virgin. It is only of man that we confess he was made; God is always the one who makes, he cannot be made in order to be. God cannot be made; but he is made into, or becomes, something for someone, in the way in which it is said of him, "Lord, you have become (or have been made into) a refuge for us"; and, "The Lord has become (has been made) my helper." How many things he has been made into, though he never was made at all! Now the Lord Christ was made man, … in order for him who was always the creator to be a creature. While remaining God, you see, he became man in order to become what he was not, not in order to stop being what he was.”

“He who dwells in the covert of the Most High He who takes shelter in the covert of the wings of the Shechinah. he will lodge in His shadow, for the Holy One, blessed be He, protects him. Moses, our teacher, hereby persuades people to take shelter in the wings of the Shechinah. the Almighty Heb. שדי, an expression of strength. “He who dwells in the covert of the Most High” is like (Song 2:3): “in His shadow I desired and sat.””

“David. Septuagint add, “it has no title in Hebrew,” and hence the Jews refer it to the preceding author, with St. Jerome, &c. But this rule is very uncertain. (Calmet) (Berthier) — Some suppose that Moses composed it when he led the Israelites out of Egypt, or in the wilderness; while others think that it is the work of David under some imminent danger. The Fathers apply it to Jesus Christ. Yet it may be considered simply as a moral instruction, (Calmet) superior in elegance to any Greek or Latin poem. (Muis) — Aid. Hebrew, “secret place.” Of heaven. Is not in Hebrew shaddai, which means, (Haydock) “the almighty self-sufficient, or destroying God.” (Calmet) — We must keep close to God by mental prayer, if we would enjoy the divine protection. (St. Gregory, Mor. vii. 7.) (Berthier)”

“As the concealing One, God is called עליון, the inaccessibly high One; and as the shadowing One שׁדּי, the invincibly almighty One. Faith, however, calls Him by His covenant name (Heilsname) יהוה and, with the suffix of appropriation, אלהי (my God). In connection with Psa 91:1 we are reminded of the expressions of the Book of Job, Job 39:28, concerning the eagle's building its nest in its eyrie. According to the accentuation, Psa 91:2 ought to be rendered with Geier, "Dicit: in Domino meo (or Domini) latibulum, etc." But the combination אמר לה is more natural, since the language of address follows in both halves of the verse.”