Lying

My friend has done something bad in her past. She regrets it and when she told me about it she made me say wallah that i would not tell anyone but people at the masjid are suspicious. They keep asking me about her and if she's done that something. If i say "i don't know" that would be a lie, because i do know. If i say "no" that would be a lie and if i say yes (the truth) that would mean that i would have to break the promise that i made my friend (in Gods name) WHAT SHOULD I DO??

Dear Brother / Sister,

Firstly, it will not be true to make a certain decision on such a subject since we don’t know all the details of the subject. But to enlighten the subject we will specify some points below:  

1- First of all a believer should cover up one’s fault. S/he doesn’t have to give information to someone who is not directly related and in charged with the event.

2- The essence for the sins is to keep secret. That is to say, it is not true to expose and to spread the sins.  

3- Only to the courts, you have to tell the truth for such the subject. To prevent a harm, an injustice or a wrong in an event that concerning the public and if our testimony will be beneficial for both the person and public then the fault is explained, otherwise we should act in accordance with the benefits of the person and the public. If saying the truth will be harmful we shall keep silent.

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