Musar על דברים 7:10

Therefore, the intelligent person will do with his wealth and his wisdom the good he can, according to the extent of his wealth and wisdom, and will add to his modesty and humility and his heart will not grow haughty and he will always worry whether this wealth is not his sole reward. Such a person belongs to those who fear that their wealth may destroy them and of whom it is said: "But who instantly requites with distraction those who reject him" (Deut. 7:10). The wise man, too, will worry whether he is among those of whom it is said: "They are wise to do evil and do not know how to do good" (Jer. 4:22). And every man is obligated to grow wiser and to understand more clearly and continue to attain through his wisdom good deeds until his wisdom can achieve no more.

And there are times when the merit of someone who is liable for excision lasts him two or three generations. And the delay in the death of evildoers is to pay their reward in this world, and so to destroy them in the world to come. For it is stated (Deuteronomy 7:10) “But who instantly repays with destruction those who hate Him - never slow with those who hate Him, but repaying them instantly.” And the thing is explained in the words of King David, peace be upon him (Psalms 92:7-8), “A brutish man cannot know, a fool cannot understand this: Though the wicked sprout like grass, though all evildoers blossom, it is only that they may be destroyed forever.” And likewise did Asaf, peace be upon him, say (Psalms 73:3-17), “For I envied the wanton; I saw the wicked at ease. Death has no pangs for them, etc. Until I entered God’s sanctuary and reflected on their fate.” Its explanation is that vengeance upon the evildoers is at their end, as it is stated (Proverbs 24:20), “For there is no future for the evil man; the lamp of the wicked goes out.”

There are other groups that do not have a share in the world to come: And they are the group of the enemies of the Lord, may He be blessed; the group of the destroyers of the vineyard of the Lord; and the group of the ones inflicting fear in the land of the living. Behold we will present their content and the proof of their punishment explicit in the Torah:
For the group of the enemies of Lord will be lost from the world to come, as it is stated (Deuteronomy 7:10), “But who requites with destruction those who hate Him to his face - never slow with those who hate Him, but requiting them to his face.” Its explanation is that he repays the reward of the commandments fulfilled by those that hate Him, in this world - in order to destroy them from [getting to] the world to come. And its Targum (translation by Onkelos) is, “And He repays those that hate Him the good that they do in front of Him, in their lives, to destroy them. And David said (Psalms 37:20), “But the evildoers shall be lost, and the enemies of the Lord shall be like heavy sheep, completely consumed in smoke.” And he mentioned the expression, “loss,” with the evildoers, as it is [used] for distress and exile - as the matter that is stated (Isaiah 27:13), “the lost who are in the land of Assyria and the expelled, etc.”; (Jeremiah 50:6), “My people were lost sheep”; [and] (Psalms 119:176), “I have strayed like a lost sheep” - and it is also [used] for death, as the matter that is stated (Psalms 119:92), “I would have been lost in my affliction”; (Esther 8:6) “at the loss of my kindred”; [and] (Leviticus 23:30) “and I will cause that soul to be lost” - meaning excision from this world. For evildoers are punished with difficulties and afflictions or with death, and they are also punished with the judgement for their deeds in the world to come. But [David] compared the enemies of the Lord to the meat of sheep, as it will become coals. Therefore, it will be “completely consumed in smoke.” Just like the fat of sheep is consumed in smoke, so too will the enemies of the Lord be consumed. For their souls will be consumed and lost from the world to come. And it is stated (Exodus 20:5), “visiting the guilt of the parents upon the children, upon the third and upon the fourth generations of those who hate Me.”

And this is something that stands to reason. For how is it possible that the Holy One Blessed be He will decrease a man's livelihood, which He has decreed for him on Rosh Hashanah because he did not want to sacrifice his set time for Torah study? And even if it happens that because of his study time he misses his profit for that day he need not worry about it, for there are many options open to the L-rd. And if not today, He will give it to him on a different day, and he can rest assured that by the end of the time for the sustenance of that year (i.e., until Rosh Hashanah, as Chazal have said), there will certainly be paid him what was decreed for him by Heaven. And all of his increased diligence and exertion will not help him one bit. For certainly he will not add anything [to his "stipend"] by transgressing the will of the Holy One Blessed be He by interrupting his set Torah study time or [his time for] giving money to charity — unless he be one who entirely denies the L-rd and His providence, of whom it is written (Devarim 7:10): "And He pays His foes to his face [in this world] to make him go lost" [in the world to come].