Musar su Deuteronomio 27:1

The thirteenth principle of repentance is to take seriously the transgressions which one has treated lightly. For example, looking at women or speaking over-much with them, or conversing about idle things, or doing nothing, or mentioning the name of God in vain. All these and many more like them are considered trivial by many people and even by great men of the day — they must be regarded as very serious matters. And there are four reasons for this : First, one should never look at the smallness of the sin but at the greatness of Him who warned against it. A parable will illustrate this. A king commanded his two servants, the one to bring him something to drink for he was very thirsty, and the other to do something that he really did not need very much; and he warned each one, on pain of death. Certainly, if either one of them disobeyed his command he would be liable to death, for they hang a man who has stolen one dinar just as they hang one who has stolen a thousand, for each one has transgressed the command of the king. In the same way the Lord has warned us concerning all of the Torah, "Keep all the commandment which I command you this day" (Deut. 27:1). And it is written, "Cursed be he that confirmeth not the words of this law to do them" (Deut. 27:26). The second reason is that when one transgresses a little matter many times, it becames a very severe matter, because the punishments for each individual transgression are combined. Thirdly, when one is accustomed to commit sins, he comes to regard them as permissible and does not guard himself against them, and he is reckoned among those who cast off the yoke of the Torah and who are "apostates with respect to one matter." Fourthly, it is the way of the evil inclination that after he conquers in some small matter, he goes on to conquer in a serious one. Therefore our Sages said, "Be heedful of a light precept as of a grave one" (Aboth 2:1). And they said further, "For one good deed draws another in its train, and one sin, another sin" (Aboth 4:2).