Usul al-Kafi
Book 5:
The Book of Belief and Disbelief

Chapter 44
Supplement to the previous chapter

730. 1. Prophet Muhammad (p): All worship has its initial fervour. Then, the fervour weakens. Whoso ever’s fervour of worship (according to my path) remains strong, he is guided and whosoever deviates from my path, he errs and goes astray. His deeds are all wasted.

Elaborating on these instructions, Prophet Muhammad (p) said:
I say my prayers and I sleep and I observe fast and terminate my fast (at its proper time) and I laugh and I weep, so anyone who deviates from my ways and my path is not in my fold.

The Prophet (p) added that death should suffice as a constant warning. Firm conviction must be enough for contentment and worship must be sufficient to keep one occupied.

(B5,C44,T1)

731. 2. Imam Jafar as-Sadiq (p): Everyone has a desire and after every desire there is a period of lapse. How fortunate is the person whose lapse is inclined towards good deeds.(B5,C44,T2)