✅Answer:

Consider the following narrations:

1 عَنْ مُعَاوِيَةَ بْنِ عَمَّارٍ قَالَ: سَأَلْتُ أَبَا عَبْدِ اللَّه عَنْ الثِّيَابِ السَّابِرِيَّةِ يَعْمَلُهَا الْمَجُوسُ وَ هُمْ أَخْبَاثٌ وَ هُمْ يَشْرَبُونَ الْخَمْرَ وَ نِسَاؤُهُمْ عَلَى تِلْكَ الْحَالِ أَلْبَسُهَا وَ لَا أَغْسِلُهَا وَ أُصَلِّي فِيهَا قَالَ نَعَمْ

📚 Al-Tahdhib, vol.2, p.362

Muawiya ibn Ammar said: I asked Imam Sadiq (peace be upon him) about wearing Sabri clothes made by Magians while they are impure and drink wine, and their women are similarly impure. Can one wear them without washing and pray in them? He replied: Yes.

2 عَنِ الْمُعَلَّى بْنِ خُنَيْسٍ قَالَ سَمِعْتُ أَبَا عَبْدِ اللَّهِ يَقُولُ لَا بَأْسَ بِالصَّلَاةِ فِي الثِّيَابِ الَّتِي يَعْمَلُهَا الْمَجُوسُ- وَ النَّصَارَى وَ الْيَهُودُ.

📚 Al-Tahdhib, vol.2, p.361

Mu'ali ibn Khunis said: I heard Imam Sadiq (peace be upon him) say: There is no problem praying in clothes made by Magians, Christians, or Jews.

3 أَحْمَدُ بْنُ عَلِيِّ بْنِ أَبِي طَالِبٍ الطَّبْرِسِيُّ فِي الْإِحْتِجَاجِ عَنْ مُحَمَّدِ بْنِ عَبْدِ اللَّهِ بْنِ جَعْفَرٍ الْحِمْيَرِيِّ أَنَّهُ كَتَبَ إِلَى صَاحِبِ الزَّمَان عِنْدَنَا حَاكَةٌ مَجُوسٌ- يَأْكُلُونَ الْمَيْتَةَ وَ لَا يَغْتَسِلُونَ مِنَ الْجَنَابَةِ وَ يَنْسِجُونَ لَنَا ثِيَاباً فَهَلْ تَجُوزُ الصَّلَاةُ فِيهَا مِنْ قَبْلِ أَنْ تُغْسَلَ فَكَتَبَ إِلَيْهِ فِي الْجَوَابِ لَا بَأْسَ بِالصَّلَاةِ فِيهَا.

📚 Al-Ihtijaj, p.484

Humayri wrote to Imam al-Zaman (peace be upon him): We have Magian weavers among us who eat carrion and do not perform ghusl after junub, and they make clothes for us. Is it permissible to pray in them before washing? The Imam replied: Praying in them is permissible.

✅As seen from the above narrations, clothes made by Magians, Jews, or Christians do not require washing before praying in them.

✅The following narration also confirms this, and additionally indicates that washing the clothes is preferable to the Imam:

4 عَنْ عَبْدِ اللَّهِ بْنِ جَمِيلِ بْنِ عَيَّاشٍ عَنْ أَبِي عَلِيٍّ الْبَزَّازِ عَنْ أَبِيهِ قَالَ: سَأَلْتُ جَعْفَرَ بْنَ مُحَمَّدٍ عَنِ الثَّوْبِ يَعْمَلُهُ أَهْلُ الْكِتَابِ- أُصَلِّي فِيهِ قَبْلَ أَنْ يُغْسَلَ قَالَ لَا بَأْسَ وَ أَنْ يُغْسَلَ أَحَبُّ إِلَيَّ.

📚 Al-Tahdhib, vol.2, p.219

Abu Ali Bazzaz narrated from his father: I asked Imam Sadiq (peace be upon him) about clothes made by the People of the Book. Can one pray in them before washing? He replied: There is no problem, but washing them is more beloved to me.

✅The preference for washing clothes made by the People of the Book is clear from the above narration, although, according to this and previous narrations, one may pray in them without washing.

✅Clothes that one specifically knows have been made impure by the People of the Book are treated differently.

✅The above narrations refer to new clothes made by the People of the Book. Used clothes that have been worn by them have slightly different rulings, which today are rarely relevant.

✅Clothes made by non-Muslims from natural leather have different rulings; for more information, refer to Question 504 on the channel.

اللَّهُمَّ صَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ

وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْرَ