Concealing other's shortcomings
If one comes to know of somebody's shortcomings it is a matter of great merit if he conceals it from others provided this shortcoming is not harmful or dangerous to others. According to Abu Huraira, our Holy Prophet has said that, “Allah shall conceal on the Dav of Judgement the shortcomings of the one conceals the shortcomings of other.” (Sahih Muslim: Kitab al Birr wa Silah)
And Aqabah ibn Amir relates that Our eternally blessed Prophet has said that, “The action of one who conceals the shortcomings of another is as if he saved a girl from being buried alive.” (Mustadrik Hakim, p. 334, vol 4)
Concealing the shortcoming means not mentioning it to others and not broadcasting or announcing it before all. But certain points should be borne in mind in this connection.
1 . It is not justified to lie to conceal another shortcoming. So if one is asked about the shortcoming he, should first try to avoid answering, but if pressed he should not say anything except the bare fact.
2. Concealing somebody's shortcoming is justified when the effect of that shortcoming is confined to the man himself, but if it might conceivably cause harm or injury to others, then it is justified to tell the person to be affected about the shortcoming. This latter action is not only justified but also meritorious provided there is no intent of harming anyone or insulting or degrading him. For instance someone is in the habit of taking money from others by subterfuge and not returning it or someone is habitual borrower and does not redeem his loans. As in both case an unaware person may be taken by surprise and lose his money, he should be informed of this habit of the borrower. Another instance is of a person who proposes to marry girl; if the giri's parents wish to know about the prospective husband, it is justified to tell the the truth. However, in all such cases, the intent should not be of harming anyone in any way. Another case is that of a person who has committed a crime which may harm the society or the community; this information must be made available to proper authorities as it is a meritorious act, if the intent is social reform and not personal revenge against the culprit.