مُوَطَّأُ مَالِكٍ
Muwatta Malik 322
Prayer in Congregation
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ جَابِرَ بْنَ عَبْدِ اللَّهِ، كَانَ يُصَلِّي فِي الثَّوْبِ الْوَاحِدِ .
Yahya related to me from Malik that he had heard that Jabir ibn Abdullah used to pray in one garment.
Arabic/English book reference: Book 8, Hadith 33