Let the words of my mouth
Meaning either his speech in common conversation, which should not be filthy and foolish, rotten and corrupt; but such as ministers grace to the hearer: or else his address to God, both in prayer and thanksgiving;
and the meditation of my heart;
his inward thoughts continually revolving in his mind; or his meditation on the word of God and divine things; or mental prayer, which is not expressed, only conceived in the mind;
be acceptable in thy sight;
as words and thoughts are, when they are according to the word of God; and as the sacrifices of prayer, whether vocal or mental, and of praise, are through Jesus Christ our Lord. The psalmist, in order to strengthen his faith in God, that he should be heard and answered in the petitions he put up, makes use of the following epithets:
O Lord, my strength,
or "rock" F12,
and my Redeemer;
who had been the strength of his life and of his salvation, the rock on which he was built and established, and the Redeemer who had redeemed his life from destruction, and out of the hands of all his enemies, and from all his iniquities.
F12 (yrwu) "rupes mea", Musculus, Junius & Tremellius, Piscator, Cocceius; "mea petra", Pagninus, Montanus, Rivetus; so Ainsworth.