Albert Barnes Commentary Psalms 16:7

"I will bless Jehovah, who hath given me counsel; Yea, my heart instructeth me in the night seasons." — Psalms 16:7 (ASV)

I will bless the Lord, who has given the counsel - Probably the reference here is to the fact that the Lord had counseled him to choose him as his portion, or had inclined him to his service. There is nothing for which a rightly affected heart is more disposed to praise God than for the fact that by his grace it has been inclined to serve him; and the time when the heart was given away to God is recalled from then on as the happiest period of life.

My reins ... - See the notes at Psalm 7:9. The “reins” are here understood as the mind, the soul. They were regarded as the seat of the affections (Jeremiah 11:20; Job 19:27).

The meaning here is that in the wakeful hours of night, when meditating on the divine character and goodness, he found instruction regarding God. Compare Psalm 17:3.

Everything then is favorable for reflection. The natural calmness and composure of the mind; the stillness of night; the starry heavens; the consciousness that we are alone with God and that no human eye is upon us—all these things are favorable to profound religious meditation.

Those who are kept wakeful by night need not find this an unprofitable portion of their lives.

Some of the most instructive hours of life are those spent when the eyes refuse to close themselves in slumber, and when the universal stillness invites contemplation on divine things.