Back to chapter 38 about modesty
Translated by Ralph Anzarouth and an anonymous friend
Lust is the antithesis of modesty and when man unites with a woman who is forbidden to him or with one of a kind forbidden to him it causes him great evil. This shortens man's life span in various ways. The physicians have said that for every person who dies as a result of other illnesses, a much greater number die as a consequence of immoral physical unions.
We can compare this trait to the bat, which is an unclean creature, which flies only at night and which enjoys depravity more than any other animal. King David said (Psalms 119, 150): "Pursuers of lewdness have drawn near; from Your Torah they have distanced themselves1," in other words, everyone who is drawn only to pursuit of depravity distances himself from Torah. King Solomon said (Proverbs 7, 27) "The ways of the grave are her house, descending to the chambers of death1." He further said (ibid. 29, 3) "One who frequents courtesans loses his fortune", and he said (ibid, 30, 15-16) "There are four which never say ‘enough’: the grave, the barren womb etc.". He further said (ibid. 30, 18-20): "There are three things which I ignore […]; these is the way of the immoral woman2." Our sages of blessed memory said (Talmud Bavli, tractate Sota 3b): "Depravity in the home is as harmful as a worm among sesame seeds." Concerning the verse (Devarim 27, 15) “Cursed is the man who makes an idol", they further said (Talmud Bavli, tractate Sota 37b): "Would a mere curse suffice for this? They deduce that this talks about adulterous [and the outcome of their act]. They say that Yoseph refutes the handsome, who wish to use their good looks as an excuse [for their lustful acts], since one may reply to him: "Were you better looking than Yoseph, who did not sin with his master’s wife3?"
Seneca said that when one seriously thinks about the outcome of depravity, it will repulse him from the start. Ovid suggested to pay no attention to a woman’s weeping since her intention is to deceive you and her eyes will give spout tears at will. Someone else said: "If all the adulterous were to be stoned, as prescribed in the Bible, there would not be sufficient stones to complete the task".
It is written in Roman literature that there was a king who, when his son was born, called to his astrologer and wise men in order to know what his future will be. They answered that if [the son] would see daylight before reaching the age of fourteen, he would lose his sight. Accordingly, the king ordered that the child be confined to a room in a tower and there he stayed until the appropriate time. The child saw no living person and no object other than his servant who brought him food and drink and all his needs. When the time arrived, the king brought him out and handed him over to the wise men to educate him, teach him the Bible and to inform him that there is justice and a Judge, and that there is a Gan Eden where the souls of the righteous are to be found, along with the heavenly angels ascending and descending, as our Sages of blessed memory described, and also that there is a Gehinom, where avenging angels order fire and brimstone to the wicked and sinful souls. They are led there by devils who administer their punishment. Afterwards they showed him all the creatures of the universe, male and female, cattle great and small, horses and donkeys, dogs and cats, poultry and fish, crawling insects and everything else. The youth asked the names of every one of these and they told him all of them. When he asked the names of women, one of them replied to him jokingly that they are called ‘devils’. The king subsequently asked his son which of these things he had seen found more favor in his eyes. He replied that those devils made a greater impression on him than all the rest. The king asked [the wise men] how his son could have seen devils, whereupon they replied that they had told the youth that women were called ‘devils’. The king then said to his son to beware of them lest they lead him to Genihom.
 Translation of this verse courtesy of Judaica Press and chabad.org
 The verse describes the ways of the immoral woman, who after her acts behaves as if she had done nothing wrong.
 See Bereshit chapter 39.
The whole book Tzemach Tzadik in Hebrew (printed in Rashi characters) can be downloaded in PDF format and read online at Hebrewbooks.org. Chapter 39 about Lust is found at pages 74-76.