7-19 (The compiler of the book narrated) that his father - may God be pleased with him - narrated that Sa’ed ibn Abdullah quoted Ahmad ibn Muhammad ibn Isa, on the authority of Muhammad ibn Abi Umayr, on the authority of Himad, on the authority of Al-Halabi, on the authority of Aba Abdullah as-Sadiq (MGB), “Whenever you are the prayer leader it suffices that you say the opening Takbir (God is Great) once aloud and say the rest in a low voice.”