A:
Everyone should offer Salah in clothes that are Tahir, as
one of the conditions of the validity of Salah is Taharah (ritual purity) from major and minor ritual impurity, and absence of Najasah (ritual impurity) in the body, clothes and place of Salah. The Prophet (peace be upon him) took off his shoes during Salah when he discovered that they had Najasah on them. These workers should therefore purify their clothes to offer Salah in the future. As for the past years, they are excused for their ignorance. (Part No. 5; Page No. 154) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.