Good parents discipline their children when they disobey. They try to keep them from harmful influences. They tell the children how to behave, and what is important. Good parents may even use "tough love" to save their children from themselves when they do something particularly self-destructive. They do this because they love their children and they want them to grow up to be good adults. HaShem is an excellent parent to Israel, his child/children, as Isaiah shows.
The first chapter of Isaiah establishes Israel as G-d's children. "I [G-d] reared children and brought them up ..." (Isaiah 1:2). This is a theme that pervades much of the Tanach. The Tanach refers to Israel as G-d's child, children, and son in many places. This theme starts in the Torah. Exodus 4:22-23 says "Then you shall say to Pharaoh, 'Thus says the L-RD: Israel is My first-born son. I have said to you, "Let My son go, that he may worship Me,..." ". Deuteronomy 1:31 says "and in the wilderness, where you saw how the L-RD your G-d carried you, as a man carries his son, all the way that you traveled until you came to this place." It seems that during the time of the wanderings, Israel was seen as a small child, which is what he was spiritually, having just received G-d's Torah. Deuteronomy 8:5-6, which is very pertinent in the discussion of Isaiah, says "Bear in mind that the L-RD your G-d disciplines you just as a man disciplines his son . Therefore keep the commandments of the L-RD your G-d: walk in His ways and revere Him." The prophets, including Isaiah, pick up this theme of Israel as G-d's children and G-d as a parent who disciplines His children. That is not to say that the prophet Isaiah continually says "my children, Israel" or a similar phrase, but that, after saying once that Israel are G- d's children, he continually shows the parental behavior of G-d.
After Isaiah's initial statement calling Israel G-d's children in Isaiah 1:2, he show how G-d chastises His children. "Ah, sinful nation! People laden with iniquity! Brood of evildoers! Depraved children! They have forsaken the L-RD, spurned the Holy One of Israel, turned their backs [on Him]. Why do you seek further beatings, that you continue to offend?..." (Isaiah 1:4-5). Here, G-d is portrayed as very much like a parent, criticizing His children, while at the same time wondering why they continue to disobey. He wants and expects a certain kind of behavior from His children, no simply sweet words or gifts, and He tells Israel so through Isaiah (Isaiah 1:11-15). It is not that sweet word and gifts are offensive to G-d, it is that His children have been disobeying Him, while continuing to talk sweetly and bring gifts. It is very much the actions of a rebellious adolescent child, who goes out of the house and disobeys their parents, while saying to them at home "You know, you are the best parents, here, I brought you something", in an effort to cover-up their misdeeds. G-d, seeing everything, knows exactly what His children are doing when they are not "acting" sweet to His "face". He tells His children that they will be shamed "because of the terebinths you desired" (Isaiah 1:29). They have been chasing after false gods, following the ways of their peer nations, instead of listening to their own Father's advice.
Having chastised Israel, His children, He tells them again what He expects of them. "Wash yourselves clean; put your evil doings away from My sight." (Isaiah 1:16). This does not mean that Israel should try and do their evil in secret, since there is nothing that is secret from G-d, but that, as the verse continues, they should "Cease to do evil; learn to do good" (Isaiah 1:16-17). G-d then goes on to give some specifics, reminding them what He requires of His children: "Devote yourselves to justice; aid the wronged. Uphold the rights of the orphan; defend the cause of the widow." (Isaiah 1:18).
G-d then offers His children hope, if only they change their ways. "Come, let us reach an understanding, -- says the L-RD. Be your sins like crimson, they can turn snow- white; be they red as dyed wool. they can become like fleece." (Isaiah 1:18). If Israel changes and does what their Father tells them, they will be forgiven and given a fresh start. Isaiah, seeming to speak for himself as well as G-d, says to his fellow children of Israel, "O House of Jacob! Come, let us walk by the light of the L-RD." (Isaiah 2:5), encouraging them to do what is right. No parent wants to give up on their children, to just turn them away without any hope. Most children genuinely want to please their parents deep down. G-d is offerings His children hope. He also offers them a reward for good behavior. Like a good parent, punishment alone is not used, rewards are used to reinforce and encourage good behavior. Isaiah 1:19 starts, "if, then, you agree and give heed, you will eat of the good things of the earth...". It is a bit like saying, "If you make your bed and quite hanging out with those bad kids, I will get you pizza and ice cream".
This promise of reward is, of course, followed by a warning of what will happen if the bad, disobedient behavior continues: "But if you refuse and disobey, you will be devoured [by] the sword..." (Isaiah 1:20). This does not mean that Israel will disappear from the face of the world, as it is later made clear, but that some of the children will be punished, and some kicked out of the house so they do not influence the remaining children adversely. This interpretation is born out by a number of passages, including "Zion shall be saved in the judgment; her repentant ones, in the retribution, but rebels and sinners shall all be crushed, and those who forsake the L-RD shall perish." (Isaiah 1:27- 28). The children that are left will be pure and good as Isaiah 1:25 says, "I will turn My hand against you, and smelt out your dross as with lye, and remove all your slag". The children will emerge from G-d's punishment without the dross, the evil. Afterwards, G-d says, "you shall be called City of Righteousness, Faithful City." (Isaiah 1:26).
The future for the children as a whole will be bright, says G-d, who know his children well. Isaiah paints a picture in chapter 2 of Israel as a light unto the peoples of the world: "And the many peoples shall go and say: 'Come, let us go up to the Mount of the L- RD, to the House of the G-d of Jacob; that He may instruct us in His ways, and that we may walk in His paths.' For instruction shall come forth from Zion, the word of the L-RD from Jerusalem." (Isaiah 2:3). This is similar to Zecheriah 8:23, which says "Thus said the L-RD of Hosts: In those days, ten men from nations of every tongue will take hold -- they will take hold of every Jew by a corner of his cloak and say, 'Let us go with you, for we have heard that G-d is with you.' " G-d knows that there is a bright future ahead for those of His children who remain faithful or repent.
As I said at the beginning of the paper, Israel are G-d's children. G-d loves Israel, and Israel is supposed to love G-d and do what G-d demands. Failure to do so results in punishment. Repentance and following G-d's will results in forgiveness. G-d's punishment purifies Israel, just as a parents punishment is supposed to improve their child. In the end, G-d know that Israel, His first-born, will return to Him, and become an example for all the other younger children in the family, that is, to all the other peoples of the world.
Tanakh: A New Translation of The Holy Scriptures According to the Traditional Hebrew Text, Jewish Publication Society, 1985