John Gill's Exposition of the Whole Bible
Psalms 104:34
My meditation of him shall be sweet,.... Of the glories, excellencies, and perfections of his person; of his offices, as Mediator, King, Priest, and Prophet, the Saviour and Redeemer; of his works of creation, providence, and redemption; of his word, the blessed truths and comfortable doctrines of it; of his providential dispensations, and gracious dealings with his people in the present state; which to meditate upon, when grace is in exercise, is very sweet, delightful, and comfortable. The Targum renders it as a petition,
"let my meditation be sweet before him;''
that is, grateful and acceptable to him: or, as the Septuagint and Vulgate Latin versions, "let my speech", discourse, colloquy, address in prayer; see Psalms 141:2, or, "let my praise", so the Arabic and Syriac versions: the spiritual sacrifices both of prayer and praise are acceptable to God through Christ; and the speech of the church, and every believer, whether in the one way or the other, is sweet to Christ, very pleasant and delightful to him, Song of Solomon 2:14.
I will be glad in the Lord: the Targum is,
"in the Word of the Lord;''
in the essential Word, the Lord Jesus Christ; in his person, the greatness, glory, beauty, and fulness of it; in his righteousness, its purity, perfection, and perpetuity; in his salvation, being so suitable, complete, and glorious.