Is a person considered responsible for the death of another if they prayed for their death, and this repeatedly occurred?

It is not permissible for a Muslim to invoke evil upon his Muslim brother, unless the latter has wronged him, and only to the extent of the wrongdoing, based on the Almighty's saying: ﴿Allah does not like the public utterance of evil, except by one who has been wronged.﴾ It is, however, recommended to forgive the wrongdoer, especially if they are relatives, as this constitutes an act of kindness, in accordance with the Prophet's (peace be upon him) saying: «And forgive him who has wronged you.»

Exceeding the limit in invoking evil upon the wrongdoer is considered aggression, as per the Almighty's saying: ﴿So, whoever commits aggression against you, then aggress against him in the same measure as he aggressed against you.﴾ Consequently, an excessive supplication will not be answered.

If someone supplicates for a person's death and that person dies, the supplicator is not considered a killer, as it cannot be definitively asserted that the death was caused by the supplication. Jurists have not mentioned this issue among the grounds for retribution (Qisas) or blood money (Diyyah), which indicates that it is not considered a cause for such. Similar incidents have been reported concerning the early Muslims, and no retribution or blood money resulted from them.