Psalm 17:3
The Lord is my firmament, and my refuge, and my deliverer, my God is my helper.
Haydock
Verse 3. Firmament. Heb. “rock and my citadel, and my deliverer. My God, (or strong one) my rock.” S. Jer. “my strong one.” The two words which are rendered “my rock,” are salhi and metsudathi. H. — David frequently retired to such places for safety. The idea was beautiful and striking. Such multiplicity of titles shews the gratitude (C.) and affection which David felt. C. — Here are nine, and we may add the three metaphorical Heb. terms, “rock, citadel, and buckler.” Can we refuse to love One from whom we have received so many favours? — And in, &c. These words are most probably cited by S. Paul, (Heb. ii. 13.) though they occur also in Isai. viii. 18. — Protector. Heb. “buckler.” Bert. — Horn. This title is given to Jesus Christ, Luke i. 69. It is an allusion to beasts which attack their opponents with their horns (Theod. Deut. xxxiii. 17.) being an emblem of strength (W.) and glory. C. — And my, &c. (2 K.) he lifted me up and is my refuge; my Saviour, thou wilt deliver me from iniquity. Heb. “violence.”
Denzinger
2133: The Authors and the Time of the Composition of the Psalms
Reply of the Biblical Commission, May 1, 1910
Question V: Whether in appearance the Davidian origin can be denied to those psalms which are cited in the Old and New Testament distinctly under the name of David, among which to be considered before the rest come: psalm 2, Quare fremuerunt gentes; psalm 15, Conserva me, Domine; psalm 17 Diligam te, Domine, fortitudo mea; psalm 31, Beati, Quorum remissae sunt iniquitates; psalm 68, Salvum me fac, Deus; psalm 109, Dixit Dominus Domino meo?–Reply: In the negative.