John Lightfoot on Psalm 30:4:
“sing unto the Lord, ye saints of his.” As God requires outward and inward worship, so a spiritual frame for inward worship may be forwarded by the outward composure. Gazing drowsiness hinders the activity of the soul, but the contrary temper furthers and helps it. Singing calls up the soul into such a posture, and doth, as it were, awaken it: it is a lively rousing up of the heart. Singing God’s praise is a work of the most meditation of any we perform in public. It keeps the heart longest upon the thing spoken. Prayer and hearing pass quick from one sentence to another; this sticks long upon it. Meditation must follow after hearing the word, and praying with the minister for new sentences, still succeeding, give not liberty, in the instant, well to muse and consider upon what is spoken: but in this you pray and meditate. God hath so ordered this duty, that, while we are employed in it, we feed and chew the cud together. “Higgaion,” or ” Meditation,” is set upon some passages of the Psalms, as Psalm ix. 16. The same may be writ up the whole duty, and all parts of it; namely, “Meditation.” Set before you one in the posture to sing to the best advantage: eyes lifted to heaven, denote his desire that his heart may be there too; he hath before him a line or verse of prayer, mourning, praise, mention of God s works; how fairly now may his heart spread itself in meditation on the thing, while he is singing it over! Our singing is measured in deliberate time not more for music than meditation. He that seeks not, finds not, this advantage in singing Psalms hath not yet learned what it means.
John Lightfoot, 1602-1675