EXPOSITION
THE occasion of this psalm is some great deliverance which has been vouchsafed to the author of it, for which he desires to praise and thank God. Of this deliverance he speaks in Psalms 40:1-3, which form a sort of introduction to the whole. He then passes on to a more general praise of God for all his glorious manifestations of himself in the history of his people (Psalms 40:5). The thought next occurs—How is he (the writer)to manifest his gratitude? And this leads to the noble outburst in Psalms 40:6-10. Not by sacrifice and offering, not by a mere legal and formal obedience, but by complete devotion of the inner man as regards himself (Psalms 40:6-8), and constant proclamation of God's goodness as regards others (Psalms 40:9, Psalms 40:10). The strain then changes. Although recently delivered from some great peril, the psalmist is still encompassed by sufferings and dangers. There are sin and infirmity within (Psalms 40:12), there are cruel enemies without (Psalms 40:14, Psalms 40:15). He therefore (in Psalms 40:11-17) betakes himself to humble supplication for himself (Psalms 40:11, Psalms 40:13, Psalms 40:17) and for the godly generally (Psalms 40:16), that God will be their Helper and Defender, and, above all, will "make no tarrying" (Psalms 40:17).
The author of the psalm, according to the title, was David, and no argument of the least weight has been brought against this view. The occasion may be conjectured to have been his restoration to his throne after the brief usurpation of Absalom. Absalom's aiders and abettors may be alluded to in Psalms 40:4, and the remnant of his party in Psalms 40:14.
The psalm falls into three portions: