Radak, on Ps 18:15

“And the words of my mouth shall be such as may please: and the meditation of my heart always in thy sight. O Lord, my helper, and my redeemer.”

“May the words of my mouth be acceptable: – i.e. what I say before Thee with my mouth, and the meditation of my heart in Thy sight: – And what I do not say with my mouth, but think in my heart and thought is the meditation of the heart – even so, let them be acceptable. For man thinks in his heart many things which he cannot frame to speak thus with his lips, therefore David says (Ps. 51:17): “O Lord, open Thou my lips”; and Solomon says (Prov. 16:1): “but the answer of the tongue is from the Lord.” O Lord, my Rock: – i.e. my Strength, in whom I put my trust in my requests, and my Redeemer: – from errors and sins of passion.”

Imported from an open dataset — not yet checked against the printed edition.