Whoever exposes himself to suspicion...

It is reported that ‘Umar b. Al-Khattâb – Allâh be pleased with him – said:

Whoever exposes himself to suspicion, let him blame only himself for whoever
suspects him. He who covers his secret is in a position to choose [to correct
himself]. Assume the best about your brother until what comes to you from him
overcomes you [and you have to change your opinion]. Never do you pay back
someone who disobeys Allâh in his dealings with you with the likes of obeying
Allâh in your dealings with him. Take righteous brothers [as friends]; acquire
them in plenty, for they are a beautification in prosperity and an aid during
calamity. Do not ask about what has not yet happened until it actually happens,
for what has happened is enough of an occupation to worry about what has not
happened. Let not your speech be given freely except to those who want to hear
it and will value it. Do not seek help in fulfilling a need you have except from
someone who wants success for you in that endeavor. Do not consult except people
who fear Allâh, and do not accompany the sinner, [lest] you learn his
sinfulness.
And be humble at the graves.

Abû Dâwûd, Kitâb Al-Zuhd article 89