[[To the chief Musician, Maschil, for the sons of Korah.]] As the hart panteth after the water brooks, so panteth my soul after thee, O God. Psalm 42:1
"That choice band of singers, the sons of Korah, are bidden to make this
delightful Psalm one of their peculiars. They had been spared when their
father and all his company, and all the children of his associates were
swallowed up alive in their sin. 
And the earth opened her mouth, and swallowed them up together with Korah, when that company died, what time the fire devoured two hundred and fifty men: and they became a sign. Notwithstanding the children of Korah died not.
Numbers 26:10,11.
They were the spared ones of grace. Preserved, we know not
why, by the distinguishing favor of God, it may be surmised that after remarkable mercy, they became so filled with gratitude
that they addicted themselves to sacred music in order that their
spared lives might be consecrated to the glory of God.
At any rate,
---we
who have been rescued as they were from going down into the pit, out of
the mere good pleasure of Jehovah, can heartily join in this Psalm, and
indeed in all the songs which show forth the praises of our God and the
pantings of our hearts after Him.
Although David is not mentioned as the
author, this Psalm must be the offspring of his pen; it is so Davidic,
it smells of the son of Jesse, it bears the marks of his style and
experience in every letter. We could sooner doubt the authorship of the
second part of Pilgrim's Progress than question David's title to be the
composer of this Psalm."
Charles Spurgeon