It is narrated from Hazrat Abdullah bin Salam (may Allah be pleased with him) that once we were discussing among ourselves as to who among us would go to the service of the Holy Prophet (peace and blessings be upon him) and ask which deed is the most beloved to Allah. But due to the awe of the Holy Prophet (peace and blessings be upon him), none of us stood up. So the Holy Prophet (peace and blessings be upon him) sent a messenger and gathered all of us one by one in his presence, and recited Surah As-Saff completely before us.