EXOD855 Although it is usually forbidden to lie, at times it is permissible to tell an untruth. The following are some examples: 1) It is permitted to tell an untruth to make peace between two people who are having a dispute, or to save someone from harm. For example, you may tell someone that a person with whom he has quarreled now regrets his behavior, even if it is not true. (Yevomos 65b; Rambam, Hilchos Gzaila Veavaida 14:13). However, you are permitted to tell an untruth to promote peace only in situations when you have no other options (Emes Knaih, p. 46). Moreover, your words should be as close to the truth as possible. (See Rashi on Braishis 27:19). 2) If you were a guest at someone’s house and the host was very hospitable, you should not tell an unscrupulous person about the hospitality extended, since he might take advantage of the host. (Hilchos Gzaila Veavaida 14:13). 3) When someone asks you for information that would constitute r’chilus (needlessly telling someone that another person said or did something against him) if you answer truthfully, you should tell a lie rather than relate that information. For example, Reuven asks you what Shimon said about him. Shimon had said something derogatory. If you tell Reuven the complete truth, you will be guilty of relating r’chilus. What should you do? If you can avoid telling an outright lie, you must do so. Very often by simply leaving out a few details your narrative will be free from r’chilus. If this is not possible, you are permitted to lie for the sake of peace. (Chofetz Chayim, Laws of R’chilus 1:8); Guard Your Tongue, pp. 137-8). 4) You are permitted to tell an untruth out of humility. For example, if someone asks you how well you know a certain tractate of the Talmud, even if you know it well, you are permitted to say that you do not. (Rashi to Bava Metzia 23b). 5) You are permitted to deceive someone who is trying to deceive you in order to save yourself from being cheated (Megilah 13b). However, you may not deceive someone as a revenge for a past wrong which has been perpetrated against you. (Orach Maisharim: Shulchan Aruch L’midos 28:2 and footnote 5). For example, if you suspect someone to be a thief and he asks you for information in order to find out when you will not be home, you are permitted to lie and say that you or someone else will be home, even though it is not true. However, if someone cheated you in a certain business deal, you are not allowed to cheat him on another occasion. 6) When someone purchases an item, you are permitted to praise what he bought even though the article does not deserve the praise. Similarly, you are permitted to praise a bride, even though she does not deserve that praise. (Ksubos 17a). 7) It is permitted to lie to save one’s life. (See Nedorim 22a). 8) A teacher is permitted to say an incorrect statement to his students in order to check their alertness and to see if they remember what they have learned. (Rambam, Hilchos Talmud Torah 4:6). 9) It is not considered lying when a person makes a statement that everyone understands to be an exaggeration. (For example, “I’ve told you a thousand times.”) (Orach Maishorim 9:11). 10) It is not considered lying to call someone who is not related to you, “My son,” or “My brother,” as a means of showing endearment. (Orach Maishorim 9:10).