Muwatta Imam Malik Book of Prayer, Hadith 73
Malik related to me from Hisham ibn Urwa from his father that the Messenger of Allah ﷺ wore a fine striped garment f rom Syria, and then gave it to Abu Jahm and took a plain, rough, garment in return. Abu Jahm asked, "Messenger of Allah! Why?" He said, "I looked at its stripes in the prayer."
وَحَدَّثَنِي مَالِكٌ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، أَنَّ رَسُولَ اللَّهِ ﷺ لَبِسَ خَمِيصَةً شَامِيَّةً لَهَا عَلَمٌ ثُمَّ أَعْطَاهَا أَبَا جَهْمٍ وَأَخَذَ مِنْ أَبِي جَهْمٍ أَنْبِجَانِيَّةً لَهُ فَقَالَ يَا رَسُولَ اللَّهِ وَلِمَ فَقَالَ " إِنِّي نَظَرْتُ إِلَى عَلَمِهَا فِي الصَّلاَةِ " .