Gemara: Rava expounded: That which the pasuk (Yeshaya 1:18) says, "Go now and we will argue, Hashem will say" – instead of "Go," it should have said, "Come"! Instead of "Hashem will say," it should have said, "Hashem said"! [The explanation is that] in the future, Hashem will say to Israel: "Go to your forefathers, and they will rebuke you."
Ein Ayah: The argument with Hashem, which the prophet uses to arouse the nation, is certainly a reason to draw closer to Hashem. Therefore, it is ostensibly more appropriate to write "come," which indicates closeness, than "go," which indicates distancing oneself from Hashem.
The presentation of a dispute between Hashem and Bnei Yisrael is absolutely not a scenario that exists on a consistent basis. Therefore, it does not seem justified to use the future tense for something which primarily occurred in the past, as the future indicates a continuous phenomenon, as it says, "This is what Iyov would do" (Iyov 1:5). It is appropriate that the way Hashem proceeds with His chosen nation is proceeding with affection, admiration, and love. Therefore, argument is a phenomenon which should remain an exceptional situation, which does not warrant the use of the future tense. This is in line with the pasuk, "With a flash of anger I hid My eyes for a moment from you, and with eternal kindness I will have mercy on you" (Yeshayahu 54:8). Therefore, it should have said, "Hashem said to you," which refers to the action at the time it occurred.
Therefore, there is an indication that the prophet is trying to describe a special characteristic that encompasses all of the steps that Bnei Yisrael experienced with great strength until the end of times. This shows the wisdom of Hashem’s righteousness and His grace to the House of Israel.
Indeed, the explanation is that in the future, Hashem will tell Israel to go to the forefathers for rebuke. When a person aligns himself with a foundation of sanctity, it is based on his free choice to follow his inclination to attach himself to that which is lofty. However, the most fundamental basis that allows a person’s choice to develop nicely in the direction of the elevated is the innate element of the nature of the spirit. Within Israel, this is an eternal legacy stemming from the sanctity of the forefathers, which has a strong connection with the entire nation.
Therefore, when over time the nation experienced a reduction in the success of its spiritual acquisitions, and the content of the inclinations towards holiness in actions and attributes was ruined, they would need something that fixes their state. Returning to their root of sanctity can occur by embracing their connection to the forefathers, which is the foundation of the national legacy of sanctity.
This is the idea of "Look at the rock from which you were hewn" (Yeshayahu 51:1). This will naturally create wonders in the mind, the emotions, and the personal characteristics. That is why Hashem recommends to them in the future to go to the forefathers. One should take a deep look at the forefathers’ natural sanctity, which infused their bodies and spirits. Then one can see how their rectitude is the model of proper behavior and compare their present actions to those of the forefathers. This will have a good impact on the spirit, as this will be a fundamental rebuke based on this connection with the forefathers, to whom the nation is attached as an eternal legacy. This form of rebuke will be successful in providing an effective remedy to all of our afflictions.