David mentions the phrase many times in the Psalms.
PSALM 18 2 The LORD is my ROCK, and my fortress, and my deliverer; my God, my strength, in whom I will trust; my buckler, and the horn of my salvation, and my high tower. 31 For who is God save the LORD? or who is a ROCK save our God? 46 The LORD liveth; and blessed be my ROCK; and let the God of my salvation be exalted.
PSALM 28 1 Unto thee will I cry, O LORD my ROCK; be not silent to me: lest, if thou be silent to me, I become like them that go down into the pit. 3 For thou art my ROCK and my fortress; therefore for thy name's sake lead me, and guide me.
PSALM 62 2 He only is my ROCK and my salvation; he is my defence; I shall not be greatly moved. 6 He only is my ROCK and my salvation: he is my defence; I shall not be moved
PSALM 71 3 Be thou my strong habitation, whereunto I may continually resort: thou hast given commandment to save me; for thou art my ROCK and my fortress.
PSALM 94 22 But the LORD is my defence; and my God is the ROCK of my refuge.
PSALM 95 1 O come, let us sing unto the LORD: let us make a joyful noise to the ROCK of our salvation.
2 SAMUEL 22 2 And he said, The LORD is my ROCK, and my fortress, and my deliverer; 3 The God of my ROCK; in him will I trust: he is my shield, and the horn of my salvation, my high tower, and my refuge, my saviour; thou savest me from violence. 32 For who is God, save the LORD? and who is a ROCK, save our God? 47 The LORD liveth; and blessed be my ROCK; and exalted be the God of the ROCK of my salvation.