“Come now, let us reason together, says the LORD: though your sins are like scarlet, they shall be as white as snow; though they are red like crimson, they shall become like wool.
18. Come now, and let us reason together ונוכחה (venivvakechah), and let us settle our dispute. — Bishop Stock. “Both of us, I and you, that we may ascertain which of us has committed an offense against the other; and if you have sinned against me, still I hope to convert you.” — Jarchi.
Though God had rejected their services as insufficient to atone for their sins while they persisted in them, yet he does not reject them as in a hopeless condition, but here calls upon them to forsake their sins, which hindered the acceptance of their services, and then all would be well. Let them not say that God picked quarrels with them; no, he proposes a method of reconciliation.
Commenting on Isaiah 1:16-20
Come now, and let us reason, together, saith the Lord,.... These words stand not in connection either with the preceding or following, but are to be read in a parenthesis, and are thrown in for the sake of the small remnant God had left among this wicked people, in order to comfort them, being distressed with sin.