Interpreters do not agree as to the meaning of this passage. Some render כי אם, ki am, “But rather, “or, “But.” I indeed allow that it is so taken in many places; but they are mistaken who read כי אם, ki am, as one word; for the Prophet, on the contrary, repeats what he had said, and that is, that God would not be propitious to the Jews except their life proved that they had really repented. The words are sometimes taken as one in Hebrew, and mean “but;” yet in other places they are often taken as separate words, as we found in the second chapter, “Though thou washest thyself with nitre;” and for the sake of emphasis the particle “surely, “is put before “though.” But in this place the Prophet simply means, that the Jews were deceived in seeking to prescribe a law for God according to their own will, as it belongs only to him either to approve or to reject their works. And this meaning is confirmed by the latter part of the verse, for we read not there כי אם, ki am, but אם, am; “ If by doing ye shall do judgment;” and then in the same form he adds, “If ye will not oppress the stranger, the orphan, and the widow;” and at last he adds, “Then (a copulative I allow is here, but it is to be taken as an adverb) I will make you to dwell in this place.”
The purport of the whole is, — that sacrifices are of no importance or value before God, unless those who offer them wholly devote themselves to God with a sincere heart. The Jews sought to bind God as it were by their own laws: he shews that he was thus impiously put under restraint. He therefore lays down a condition, as though he had said, “it belongs to me to prescribe to you what is right. Away, then, with your ceremonies, by which ye think to expiate your sins; for I regard them not, and esteem them as nothing.” What then is to be done? He now shews then, “If you will rightly order your life, ye shall dwell in this place.”
For yesterday the Prophet exhorted the people to repent; and he employed the sentiment which he now repeats. He commanded the people to come to God with an upright and pure mind; he afterwards added another sentence, “Trust not in words of falsehood, saying, The Temple of the Lord, “etc. He now again repeats what he had said, “If ye will make your ways good.” He shews now more clearly that no wrong was done to the people when God repudiated their ceremonies; for he required a pure heart, and external rites without repentance are vain and useless. This then is what the Prophet had in view: “Though God seems to treat you with great severity, he yet promises to be kind to you, if you order your lives according to his law: is this unjust? Can the condition which is proposed to you by God be liable to any calumnies, as though God treated you cruelly!” This then is the meaning of the Prophet.
If ye will make good your ways, that is, if your life be amended; and if ye will do judgment, etc. He now comes to particulars; and first he addresses the judges, whose duty it was to render to every one his right, to redress injuries, to pronounce what was just and right when any contention arose. If then, he says, ye will do justice between a man and his neighbor, that is, if your judgments be right, without favor or hatred, and if no bribes lead you from what is right and just, while pronouncing judgment on a case between a man and his brother.