Man Lā Yaḥḍuruh al-Faqīh
Hadith 802802 - وَ سَأَلَ دَاوُدُ اَلصَّرْمِيُّ أَبَا اَلْحَسَنِ عَلِيَّ بْنَ مُحَمَّدٍ عَلَيْهِ اَلسَّلاَمُ فَقَالَ لَهُ: إِنِّي أَخْرُجُ فِي هَذَا اَلْوَجْهِ وَ رُبَّمَا لَمْ يَكُنْ مَوْضِعٌ أُصَلِّي فِيهِ مِنَ اَلثَّلْجِ فَكَيْفَ أَصْنَعُ قَالَ «إِنْ أَمْكَنَكَ أَنْ لاَ تَسْجُدَ عَلَى اَلثَّلْجِ فَلاَ تَسْجُدْ عَلَيْهِ وَ إِنْ لَمْ يُمْكِنْكَ فَسَوِّهِ وَ اُسْجُدْ عَلَيْهِ.
Hadith.802 - Dawud Al-Sarmi asked Abu Al-Hasan Imam Ali ibn Muhammad Al-Hadi (as) about going on a journey where there may be no place to pray except on snow. How should he pray in such a case?
Imam (as) replied: "If you can avoid prostrating on the snow, then do not prostrate on it. But if it is not possible, then level it and prostrate on it."