What is the ruling on what some people say, “Ya Rahmat Allaah (O Mercy of Allaah)”?
Praise
be to Allaah.
This
is not permitted, this is like calling upon one of the attributes of
Allaah).
From Fataawa Samaahat al-Shakh Muhammad ibn Ibraaheem (may Allaah have mercy on him) 1/117