There is an ancient saying, "The greatest evil is lust." I believe that there is definitely some truth to it.
 
By violating moral standards on lust, human beings have created significant amounts of karma. Before the decline in moral standards, people frowned upon those who had an attachment to lust.
 
In China during the Qing Dynasty (1644 – 1911 AD), Ji Xiaolan (1724 – 1805 AD), was a famous official and the chief editor of Siku Quanshu (“Emperor’s Four Treasuries”: the largest collection of books in Chinese history). He wrote a book called Yue Wei Cao Tang Biji (“The Thatched Study of Close Scrutiny”) in which he recorded many fantastic stories he had heard or personally experienced. One of the stories goes as follows:
 
The emperor sent an officer to Taiwan on official business. On his way to Taiwan he stayed at an inn. While there one day, he saw a gorgeous girl peeking over a wall into the courtyard where he was staying. Loudly and angrily, he rebuked her and sent servants to search for her, but they didn't find her.
 
While sleeping at night, the envoy was awakened by a sound and a piece of tile flying onto his pillow. Angry, he shouted, "What monster is out there who dares to insult the emperor's envoy?"
 
A girl's voice came from outside the window, "You are a fortunate official. I tried to avoid you during the day, but you saw me, scolded and searched for me. I did not want the gods to know about this and get blamed. Hence, I was really worried."
 
"However, when you went to bed, you were thinking that possibly I was the daughter of the owner of this inn. You were conceiving a plan to have me as your second wife. Of course you are not aware that any thought you entertain, the gods and evil spirits will know about it. Whenever a person conceives an evil thought, it will attract the harassment of an evil spirit. Under this circumstance, the gods will not fault the evil spirit. Hence, when I threw a tile at you, you really had no right to be angry."
 
Listening to her explanation, the envoy felt dejected and ashamed. Before daybreak, he ordered his servants to pack up and leave.
 
From the above story we can see where such sayings by the ancients as "There are gods three inches above everyone’s heads," and "When you entertain a thought, all of heaven and earth knows about it" come from. As soon as a person conceives a lustful thought, God will know about it and will despise the person. It will also be all right for an evil spirit to harass this person. Thus, one must not say or act in an obscene way, and must also avoid entertaining any wanton thoughts.
 
色欲邪心动　神明看不起
 
古语有云：万恶淫为首。这句话的确有一定的道理，人类在两性方面违背人类道德犯罪所造的业力是非常大的。在人类道德观念变异之前，人们对色欲心很重的人也都是很轻视的。清代编定《四库全书》的一代名臣纪晓岚所写的《阅微草堂笔记》一书中，收集了当时很多的奇闻轶事，其中就有这样一则记载。
 
有一位奉皇命去台湾的使臣，途中住在驿站的馆舍里。忽然发现有个艳丽的女子扒在墙头往院里窥探，他便大声加以怒斥，以至于到外面搜索一番，却一无所获。这位使臣睡到半夜，忽然听到当当一声，有一瓦片从外面被丢了进来，砸到他的枕边。使臣大怒，大声喝问道：“何方妖怪，胆敢侮弄天子的使臣？”只听窗外一个女子朗声答道：“你禄命大，白天我一时回避不及，冲撞了你，惹你又是呵斥，又是搜索。我害怕这事被神明察觉，可吃罪不起，心里一直惴惴不安。可是你刚才睡在床上，却胡思乱想，心生邪念，把我当作那驿站里老兵的女儿，打算如何耍手段，娶来做你的小老婆。可你哪里知道，只要人心里的念头一动，鬼神立刻就知道了。人有邪心，必会招来邪鬼的骚扰，就是神明知道了也不会责备邪鬼。因此我就投一块瓦片给你作为相报，你这有甚么可恼火的？”使臣听了，心里又惭愧又沮丧，等不及天亮，就命仆人收拾行装，离开这馆舍。
 
从这则记载中我们可以看到，中国古人说的“抬头三尺有神明”，“人心生一念，天地尽皆知”真的是太有道理啦，人只要色欲邪念动一动，神明立刻就知道了，马上就瞧不起那个人了，就是邪鬼去骚扰他，也不会加以斥责了。这样看来不光是不能在行为与言语上犯邪淫之罪，就是在思想上也不能动邪淫的念头呀。