1. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad ibn ‘Isa from al-Hassan ibn Mahbub from Sa’D ibn abu Khalaf from abu al-Hassan Musa (a.s.) who to one of his sons has said the following
“My son, you must work hard and do not allow your soul to lead you out of a feeling of always falling short in worshipping Allah, the Most Majestic, the Most Holy, and in obedience to Him; Allah is not worshipped as truly as He should be worshipped.”