49:12 O You who have chosen to be graced with belief! Avoid suspicion, for suspicion in some cases hurts your own ‘self’. Do not spy and do not back-bite one another. Would any of you like to eat the flesh of his dead brother? Nay, you would detest it! Be mindful of God. Certainly, God is Relenting, Merciful.
The Quran condemns gossiping, backbiting, suspicious thoughts as well. Something that may seem innocuous may have profound consequences so why do it?