الكافي 2/2/30/6

6. Ali has narrated from his father who has said the following: “Once I saw ‘Abd Allah ibn Jundab in ‘Arafat but I had not seen any stay (spending the ninth day of Dulhajj) in ‘Arafat better than that. He continued stretching his hands to the sky and his tears flow on his both cheeks all the way to the ground. When people left I said to him, ‘O abu Muhammad, I have never seen a wonderful performance in ‘Arafat such as yours.’ He said, ‘By Allah I did not pray for anything but for my brothers (in belief) and that is because of abu al-Hassan Musa عليه السلام who told me that whoever prays for his brothers (in belief) in his absence is called from the Throne, ‘(O servant of Allah) you will have one hundred thousand times as much reward as one may for his prayer receive,’ thus, I did not like to leave one hundred thousand guaranteed for only one of mine, of which I am uncertain whether it is accepted or not.’”