By this isnad from al-Husayn b. Sa`id from Ayman b. Mahraz from Muhammad b. al-Fadl from Abu Hamza al-Thumali from Abi Ja`far . He said:

There is not a worshiper from our Shi`a except that when he rises to pray, there is an angel for every person that opposes him praying behind him and supplicating to Allah on his behalf until he completes his prayer.