That is an excellent point I hadn’t even considered. Yes, even in the Old Testament the Rock is not a sinful or fallible image. It is a divine image.
Psalm 61:2
From the end of the earth I call to You when my heart is faint; Lead me to the rock that is higher than I.
2 Samuel 22:2
He said, The Lord is my rock and my fortress and my deliverer;
2 Samuel 22:3
My God, my rock, in whom I take refuge, My shield and the horn of my salvation, my stronghold and my refuge; My savior, You save me from violence.
2 Samuel 22:47
The Lord lives, and blessed be my rock; And exalted be God, the rock of my salvation,
Psalm 18:2
The Lord is my rock and my fortress and my deliverer, My God, my rock, in whom I take refuge; My shield and the horn of my salvation, my stronghold.
There are so many more divine rock allusions in the OT, but here is just one additional example. It equates the rock to our Redeemer.
Psalm 19:14
Let the words of my mouth and the meditation of my heart Be acceptable in Your sight, O Lord, my rock and my Redeemer.