16 Wash yourselves, make yourself clean.
Put away the evil of your doings from before my eyes.
Cease to do evil. 17 Learn to do well.
Seek justice.
Relieve the oppressed.
Judge the fatherless.
Plead for the widow.” 18 “Come now, and let us reason together,” says Yahweh:
“Though your sins be as scarlet, they shall be as white as snow.
Though they be red like crimson, they shall be as wool. 19 If you are willing and obedient,
you shall eat the good of the land; 20 but if you refuse and rebel, you shall be devoured with the sword;
for the mouth of Yahweh has spoken it.”

Matthew Henry's Commentary on Isaiah 1:16-20

Commentary on Isaiah 1:16-20

(Read Isaiah 1:16-20)

Not only feel sorrow for the sin committed, but break off the practice. We must be doing, not stand idle. We must be doing the good the Lord our God requires. It is plain that the sacrifices of the law could not atone, even for outward national crimes. But, blessed be God, there is a Fountain opened, in which sinners of every age and rank may be cleansed. Though our sins have been as scarlet and crimson, a deep dye, a double dye, first in the wool of original corruption, and afterwards in the many threads of actual transgression; though we have often dipped into sin, by many backslidings; yet pardoning mercy will take out the stain, Psalm 51:7. They should have all the happiness and comfort they could desire. Life and death, good and evil, are set before us. O Lord, incline all of us to live to thy glory.