Rules about Performing Salah (Prayer) in an Unclean Cloth Regardless One Knows it or Not

8. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Ali ibn al-Hakam from al-‘Ala’ from Muhammad ibn Muslim who has said the following: I once asked one of the two Imam, ‘Alayhim al-Salam, about a man who finds blood in clothes of his brother while he is performing Salah (prayer). He (the Imam) said, ‘He is not required to inform him until he completes his Salah (prayer) again.’”