836. hadíth
وَ سَأَلَ مُعَاوِيَةُ بْنُ عَمَّارٍ أَبَا عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ: عَنِ اَلصَّلاَةِ عَلَى اَلْقَارِ فَقَالَ «لاَ بَأْسَ بِهِ.
Muawiya ibn Ammar asked Imam Jafar ibn Muhammad Al-Sadiq (a.s) about praying on qār (bitumen or tar). The Imam said: "There is no issue with it”.