832. hadíth
وَ سَأَلَ اَلْمُعَلَّى بْنُ خُنَيْسٍ أَبَا عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ: عَنِ اَلصَّلاَةِ عَلَى اَلْقُفْرِ وَ اَلْقِيرِ فَقَالَ «لاَ بَأْسَ بِهِ.
Al-Mu'alla ibn Khunays asked Imam Jafar ibn Muhammad Al-Sadiq (a.s) about praying on qufr (bare ground or desert soil) and qīr (a type of tar or pitch). Imam (a.s) said: "There is no issue with it”.