In the Torah portion of Balak,1 we read about how the Jews sinned with the daughters of Moab. This sin led to a plague that killed 24,000 Jewish people.

Our Sages teach that the daughters of Moab enticed the Jews by dressing indecently,2 behavior that is alien to traditional Jewish values. The Midrash states:"When the Children of Israel went down to Egypt, they behaved with modesty—each person living in his own tent. As the verse states: 'Each man and his household came.'3 Reuben did not look at Simeon's wife, nor did Simeon look at Reuben's wife. Rather, each man lived modestly within his own tent. Even when the population of men numbered 600,000 in the desert, no one placed the opening of his tent opposite the opening of his friend's tent."4

Our Sages established various safeguards to protect us against immorality. They recognized that in order to overcome natural temptations, a person must control his sight and thoughts5—the faculties through which he can be led astray.6

Yichud

King David forbid any unmarried man and woman to be secluded togetherAccording to Maimonides,7 the most common cause of a forbidden union is a man and woman – not married to each other – being secluded together in a private setting. (For a thought-provoking article on this subject, see A Friend's Divorce.)

Most authorities8 consider it a Torah violation for a Jewish man and woman who are forbidden to marry one another to be secluded together at any time (e.g., a man together with a married woman). King David established an additional prohibition, forbidding any unmarried man and woman (even if they are not forbidden from marrying each other) to be secluded together.9 Such forbidden seclusion is referred to as yichud. The court of Shammai and Hillel added that a Jewish man may also not be secluded with a Gentile woman.10

The following are several relevant details of this law:11

  • A man may not be alone with a girl above the age of three. A woman may not be alone with a boy above the age of nine. There is no upper age limit to these prohibitions.
  • If the man and woman are in an area that is visible from a public thoroughfare, or if the area is open to the public such that someone may enter at any time, it is not considered yichud.
  • These prohibitions apply to single people, even if they are dating each other or engaged, until they are actually married.

Additional details of the laws of yichud are beyond the scope of this article.

Purity in Speech

One should not converse excessively with members of the opposite sex.12 Certainly one may not talk, with anybody, about topics that may lead to sinful thoughts.

A man may not inquire about the welfare of a woman in a manner which shows that he is attracted to her,13 but his inquiry is permissible if it stems from genuine concern for her wellbeing or merely from politeness.14

Purity in Sight

Our Sages forbade a man to look at any woman for the purpose of enjoying her beautySince men are easily aroused by visual stimulation, our Sages forbade a man to look at any woman – "even at her pinky"15 – for the purpose of enjoying her beauty, and certainly if she is dressed immodestly. In fact, if one knows that there will be women dressed immodestly on a particular road, it is advisable that he not take that road, unless there is no alternate route.16

  • A man may not even look at the colored garments of a woman he knows, even if she's not wearing them.17
  • A man should not walk behind a woman, rather he should walk on the side or overtake her.18
  • (On a similar note, a man may not smell the perfume that a woman who is forbidden to him is wearing.19)

Purity in Sound

A man may not listen to the voice of a woman singing, other than his wife and members of his immediate family.20 A man may also not listen to a recording of a woman singing if he has seen her or her picture even once.21 Some authorities forbid a man to listen to a recording of a woman singing even if he never saw her.22

Purity in Touch

A man may not hug or kiss a woman other than his wife, with the exception of one's grandmother, mother,23 daughter, and daughter's daughter.24

Purity in Thought

One may not entertain thoughts of sin. If a sinful thought enters one's head, he should immediately turn his thoughts to holy matters.25

The best way to achieve purity in thought is by filling one's mind with Torah study and holy thoughts. In the words of Maimonides: "A person should always turn himself and his thoughts to the words of the Torah and expand his knowledge in wisdom, for the thoughts of forbidden relations grow strong solely in a heart which is empty of wisdom."26

One who succeeds in remaining pure in these matters is considered holy.27