This has a quotation within a quotation. It can be stated as an indirect quotation. Alternate translation: "He will say that I am his Father, his God, and the rock of his salvation." (See: [[rc://en/ta/man/translate/figs-quotesinquotes]] and [[rc://en/ta/man/translate/figs-quotations]])
Yahweh protecting and saving David is spoken of as if Yahweh were a high rock that David could stand on top of for protection from enemies. (See: [[rc://en/ta/man/translate/figs-metaphor]])