When is it okay to lie?

Very, very rarely.

Hashem knows when and how to go about that.  Hashem told Avraham Aveinu that Sarah Eimainu referred to herself as "old," when actually she had referred to him as old, and Rashi says that shina hakasuv mipnai hashalom, Hashem wanted to preserve their shalom bayis. (Braishis 18:12-15)  Rav Nisan Alpert, ZT'L in Limudei Nisan, reminds us that such distortions of the truth must be very carefully limited.

In Haksav v'Hakabala, Rav Yaakov Zvi Meklenburg points out a different lesson from this episode.  Sarah is accused of laughing at the news that she will bear a child to Avraham, and she denies having laughed.  The Torah concludes the story with the words, "no, you did laugh!"  What does this mean?  Are we to understand that Sarah was accused of laughing, denied it, and the Torah concludes by saying that told an outright lie?  No, she did not.  She is criticized nonetheless.  Here is Rav Meklenburg's analysis:

Some explain it that Hashem told Avraham that Sarah had laughed saying to herself, "How could I bear a child now that I am so old?" referring to Sarah's statement "After I have aged (acharei bilosi) I will bear a child?"  If we understand it this way [that Hashem did not alter her words; she was describing herself, not her husband], then Sarah's statement, "I did not laugh" is an outright lie.  However, according to our sages who say that Hashem changed her words and told Avraham she had laughed because of her age when actually she had laughed because of his age, this teaches us that it was acceptable to alter the truth to preserve peace?€¦. Therefore she did not lie.

It is comparable to the following situation.  Reuven said, "I will eat grapes today, but I will not eat figs."  Reuven then heard Shimon say to someone else, "why did Reuven say that he will not eat grapes today?"  Upon hearing this, Reuven said, "I swear that I did not say that I will not eat grapes today!" Can we say that Reuven lied?  It is the same thing; when Sarah heard the words of the angel saying that she laughed because she didn't believe that she could bear a child, she replied that she did not laugh.  This was not a lie. [She had not laughed at the possibility that she could bear a child.  She had laughed at hearing that Avraham could father a child.]

So why does the Torah end this story by saying that Sarah denied laughing yet she had laughed?  Because even though she did not lie, she was not entirely truthful.  By her general statement, "I did not laugh," she implied that she had not laughed at all.  We learn a very important lesson from this: the extent to which people of distinction have to guard themselves from the trap of falsehood, even from saying something that is not an outright lie.  If there is an implication in yours words that is not entirely truthful, you should distance yourself from it.

People of distinction?  To whom is that addressed?  In Hebrew, the term is anshei maala, people of high caliber.  That would include every one of us who hopes that our children look up to us.  Every one of us is cautioned to be careful not only not to lie, but to be entirely truthful.  We ponder that thought in our meditations at the end of every Amidah.  We don't say, elokai n'tzor lishonei ma'rah u'siforsei midabair sheker; we ask for help in avoiding mirmah, distortions, half truths, deceit.

Hashem knows when to be mishane mipnai hashalom. 

We need to be as careful as the first generation amora Rav was.

The gemara (Yevamos 63a) tells the story:

Rav was constantly tormented by his wife.  If he told her, 'Prepare me lentils', she would prepare him small peas; [and if he asked for] small peas, she prepared him lentils.  When Rav's son Hiyya was older he would tell his mother [his father's instructions] in the reverse order. [e.g. If Rav told Hiyya that he wanted lentils, Hiyya told his mother that his father had asked for peas.  As a result, she prepared what Rav had actually wanted, thinking he wanted something else.]  "Your mother," Rav once remarked to him, "has improved!"  'It was I', the other replied, "who reversed [your orders] to her." Rav said to his son, "This is what people say, 'Your own offspring teaches you reason.'  You, however, must not continue to do so for it is said, "They have taught their tongue to speak lies?€¦" (Yermiahu 9:4)

We might think that the improvement in the relationship between Rav and his wife would justify Hiyya's lies to his mother.  After all, he wasn't lying to gain benefit for himself or to shield himself from punishment.  He was just "adjusting the truth" to help his parents get along.  His father told him that although it was a reasonable solution, it was not acceptable.

Here are two examples of lies that provide reasonable solutions and are not acceptable.   

"There's no more candy in the cabinet."

There is more candy in the cabinet but your daughter can't see it.  You don't want to tell her the truth, and tell her that you're not willing to give it to her because you're sure she'll argue with you, cry, or throw a tantrum.  It's easier to just lie.  It will become a lot harder when she finds out that there is more candy in the cabinet, and that you believe it is okay to lie in order to avoid an unpleasant situation.   I'm sure you didn't mean to teach her that.  I'm equally sure that she will learn that from you.

"I told you that I would play a game with you when you finished your supper, and you did finish your supper, but now that you called your brother a bad name, I won't play with you."

It may seem reasonable to you to fail to keep your word because you have a justification, but it's not acceptable because your child will learn how to justify breaking his promises.

Keep your word.  Tell your child that you will play the game with her because she did eat her supper.  Tell her you'll play the game after she tells you how she will better express herself to her brother next time, instead of calling him a bad name.

Rabbi Yitzchak Shmuel Ackerman is a Licensed Mental Health Counselor with specialties in marriage, relationships, and parenting.  He works with parents and educators, and conducts parenting seminars for shuls and organizations.  He can be reached at 718-344-6575.