Al-Kāfi - The Book of Prayer

Chapter: Objects on Which Sajdah Is Permissible and What Is Undesirable َّدُ بْنُ يَحْيَى عَنْ ٠َّدِ بْنِ الْحُسَيْنِ أَنَّ بَعْضَ أَصْحَابِنَا كَتَبَ إِلَى أَبِي الْحَسَنِ الْ٠َاضِي (عَلَيْهِ الْسَّلا٠) يَسْأَلُهُ عَنِ الصَّلاَةِ عَلَى الزُّجَاجِ قَالَ فَلَ٠َّا نَفَذَ كِتَابِي إِلَيْهِ تَفَكَّرْتُ وَقُلْتُ هُوَ ٠َّا أَنْبَتَتِ الأرْضُ وَ٠َا كَانَ لِي أَنْ أَسْأَلَهُ عَنْهُ قَالَ فَكَتَبَ إِلَيَّ لاَ تُصَلِّ عَلَى الزُّجَاجِ وَإِنْ حَدَّثَتْكَ نَفْسُكَ أَنَّهُ ٠َّا أَنْبَتَتِ الأرْضُ وَلَكِنَّهُ ٠14.

Muhammad ibn Yahya has narrated from Muhammad ibn al-Husayn who has said the following: “Certain ones of our people wrote to abu al-Hassan, the previous one (a.s.), asking about Salah (prayer) on glass. He has said that when my letter finished I thought and said to myself that it is something that grows from earth, so I do not need to write and ask him (the Imam).

He (the Imam) wrote to me, ‘You must not perform Salah (prayer) on glass even though your soul has spoken to you that it is of what earth grows. However, it is from salt and sand and they both are metamorphosed.’” رسل - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (15/150))