David
Psalm 107:21BSB·traditional attribution

Let them give thanks to the LORD for His loving devotion and His wonders to the sons of men.

John Calvin Reformed @genevareformer

PSALM 107 The Psalmist teaches us, in the first place, that human affairs are not regulated by the fickle and uncertain wheel of fortune, but that we must observe the judgments of God in the different vicissitudes which occur in the world, and which men imagine happen by chance.

Commenting on Psalm 107:1-43

C.H. Spurgeon Reformed Baptist @princeofpreachers

Oh that men would praise the Lord for his goodness, and for his wonderful works to the children of men. It is marvellous that men can be restored from sickness and yet refuse to bless the Lord. It would seem impossible that they should forget such great mercy, for we should expect to see both themselves and the friends to whom they are restored uniting...

Matthew Henry Presbyterian @wholebiblehenry

Bodily sickness is another of the calamities of this life which gives us an opportunity of experiencing the goodness of God in recovering us, and of that the psalmist speaks in these verses, where we may observe, I. That we, by our sins, bring sickness upon ourselves and then it is our duty to pray, Psa 107:17-19. 1.

Commenting on Psalm 107:17-22