John Calvin Commentary Isaiah 58:9

"Then shalt thou call, and Jehovah will answer; thou shalt cry, and he will say, Here I am. If thou take away from the midst of thee the yoke, the putting forth of the finger, and speaking wickedly;" — Isaiah 58:9 (ASV)

Then shalt thou call. Isaiah develops what he had previously begun: that everything will prosper well for the Jews if they are just, blameless, and free from doing wrong to anyone, so that it will demonstrate their piety and religion. He declares what is said by Hosea (Hosea 6:6) and repeated by Christ, that mercy shall be preferred to sacrifice (Matthew 9:13; Matthew 12:7). Thus, after having spoken of the duties that people owe each other, and declared that it will be well with those who perform those duties, he adds, Then shalt thou call, and the Lord will listen to thee. The chief part of our happiness is if God listens to us; and, on the other hand, nothing could be more miserable than to have Him as an enemy.

To test our faith, He attributes to our prayers what He gives willingly and by free grace. For if He always gave His blessings while we were asleep, the desire to pray would become completely cold, and indeed would stop altogether; and so the kindness of God would be an encouragement to laziness.

Although He anticipates us by His free grace, yet He wishes that our prayers for His blessings should be offered, and therefore He adds, Thou shalt cry, and he shall say, Behold, here I am. This promise also contains an exhortation, that we may not remain idle. When He says that He is present, this indeed is not visible to our eyes; but He gives a practical declaration that He is near and reconciled to us.

If thou shalt take away from the midst of thee the yoke. In the latter part of the verse, He again repeats that God will be reconciled to the Jews if they repent. Under the word “yoke,” He includes all the oppressions that are inflicted on the poor; as if He had said, “If you will cease to trouble your brethren, and will refrain from all violence and deceit, the Lord will give you every kind of blessing.”

And the pointing of the finger. This includes every kind of attack; for we are said to “point the finger,” when we threaten our neighbors, treat them cruelly, or commit any violence.

And speech of vanity, or unprofitable speech. This is the third class of acts of injustice, by which we injure our neighbor when we deceive him with cunning and deceitful words or flatteries; for every iniquity consists either of concealed malice and deceit, or of open violence.