Moussar sur Les Psaumes 84:7

And if a man wishes to cleave to this trait of savlanuth, let him reflect always on the punishment for sins in Gehinnom and through gilgul [metempsychosis]. As Chazal have said (Eruvin 19a) on Psalms 84:7: "ovrei be'emek habacha mayan yeshituhu": "Ovrei" — these are the transgressors [ovrim] of the L-rd's will; "emek" — Gehinnom is deepened [ma'amikim] for them; "habacha" — they cry [bochim] and shed tears as the well of Shitin [mayan shel shitin (into which the remainder of the alter libations was poured)]." And it is known that the fire of the first level of Gehinnom is sixty times more intense than ours; of the second level, sixty times more intense than that of the first level. And thus the punishment redoubles itself in all the [succeeding] levels. And Ramban has already written in Sha'ar Hagmul that one moment in Gehinnom is more excruciating than all the afflictions of Iyyov all of his days. And it is also known that the punishment of gilgul is more excruciating than the punishment of Gehinnom.

The letter "Yud": REVERENCE - with reverence you cannot go wrong because it to guards against all evil. It is known that there is an external reverence, which fears punishment in this world and the next, for many pains afflict the wicked and reproofs for sin, to the extent that no one can fathom the great evil that the soul of the wicked endures in the world to come. They say that if a person were to suffer in his life as Job suffered, it would not be as a drop in the sea against the anguish of the day of death. And all the anguish of the day of death is not as a drop in the sea against the sufferings of the world to come, which empower the wicked to endure their suffering. Those who pass through the valley of weeping shall turn it into a spring (Psalm 84:7). Our sages, may their memory be a blessing, interpreted (Eruvin 19a) that we cause rivers of tears to flow. Indeed, a person must, while in this world, protection for his soul and consider the benefit for a transgression relative to its loss. He should have complete faith and believe that the Holy One, blessed be He, doesn’t become permissive even for the smallest moment.