Because thou hast made the LORD, which is my refuge, even the most High, thy habitation;
Because thou hast made the Lord, (which is) my refuge, (even) the Most High, thy habitation - rather, as the Hebrew has the order, 'Because thou, O Lord, (art) my refuge, thou hast made the Most High thy habitation' (cf. Psalms 90:1). In the first clause the person being taught by the Psalmist responds to his exhortation, using the first person "my," as in Psalms 91:2, "I ... my." In the second clause the Psalmist resumes the character of teacher, addressing the learner with "thou ... thy." See on this change of person the introductory remarks. The close of this first part of the psalm is marked by the repetition of the same thought as at the close of the introduction (Psalms 91:2).
Christ responds to the inspired Word, which guarantees His preservation by the Father from the foe. The reason is, "because thou Lord, art my refuge;" to which the Church replies, "thou hast made the Most High thy habitation."