Answer:
(Fatwa: 1308/1308=M/1430)
Sweat is tahir (clean), if cloth is wet with sweat it will not be regarded unclean. Thus the bench or chair will not be regarded as unclean and you can perform salah in those clothes.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
