رحمة الله عليه / رحمة الله عليها / رحمة الله عليهم
Raḥmah Allāh ʿAlayh (ʿAlayhā or ʿAlayhim)
“May God’s mercy be upon him (her or them).” It is said whenever a departed Muslim is mentioned by name.
What it means
Raḥmah Allāh ʿalayh means “may God’s mercy be upon him”. The form for a woman is ʿalayhā, and for several people ʿalayhim. Muslims say it after the name of a Muslim who has died, as a prayer that God will have mercy on him. It is closely related to the phrase raḥimahu Allāh, “may God have mercy on him”, with the same meaning. Said in conversation, in a sermon or when the name of an earlier scholar is cited, it keeps the dead in the prayers of the living and expresses the respect the community owes to those who came before.
Term and Arabic as listed in Ismail al Faruqi, Toward Islamic English (International Institute of Islamic Thought, 1995), p. 60, listed as RAḤMAH ALLAH ‘ALAYH (‘ALAYHĀ or ‘ALAYHIM).. The definition is restated here.