What is the ruling on supplicating against a Muslim, and what are the impediments to a prayer being answered?

A Muslim is not permitted to supplicate against his Muslim brother, unless he has been wronged, and his patience in refraining from supplicating is better for him. Among the impediments to the acceptance of supplication is transgressing in it, such as supplicating for sin or the severance of kinship ties, as the Prophet, peace and blessings be upon him, said: "The supplication of a servant continues to be answered as long as he does not supplicate for a sin or the severance of kinship ties."