Two healthy camels were brought for the Holy Prophet of Islam (s.a.). Holy Prophet (s.a.) turned towards his followers and announced: "Can anyone among you prays two rak'ats with sincerity and worldly thoughts does not enter his mind while doing so? I will reward him with one of these camels." None of them spoke, there was still silence. He repeated this a few times. But, the companions did not move from their place. Ali (a.s.), stood up and accepted this challenge saying,"I will perform such kind of Salaat."
Holy Prophet (s.a.) replied: "Nice, go on."
Hazrat Ali (a.s.) started his Salaat. While he was performing it and was near completion. Jibraeel descended to the Holy Prophet (s.a.) and whispered to him that Allah the Almighty says that to give a camel to Ali.
Holy Prophet said to Jibraeel: "My condition was, that during the performance of Salaat the world should not come into the mind, but, when Ali was in Tashah-hud, he was thinking that which healthy camel he will select."
Jibraeel said:"Allah the Almighty says that Ali was thinking for the healthier camel so that he can slaughter it and distribute its meat to the needy and the destitute. His intention was for Allah and not for himself nor for this world."
Holy Prophet (s.a.) handed over both the camels to Hazrat Ali (a.s.). Allah praised Ali (a.s.) in the following ayat:
The Holy Prophet (said): "Anyone who performs two rak'ats of Salaat and does'nt bring the worldly thoughts in his mind, Allah is satisfied with him and He forgives all his sins."