Sunan Ibn Majah, Volume 4, Book 32, Hadith 3604 (DarusSalam) ⓘ

It was narrated that Qais bin Sa’d said: “The Prophet came to us and we gave him some water with which to cool down. He bathed, then I brought him a yellow blanket, and I saw the traces of Wars (the yellow dye) on the folds of his stomach.”

حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، عَنِ ابْنِ أَبِي لَيْلَى، عَنْ مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ مُحَمَّدِ بْنِ شُرَحْبِيلَ، عَنْ قَيْسِ بْنِ سَعْدٍ، قَالَ أَتَانَا النَّبِيُّ ـ صلى الله عليه وسلم ـ فَوَضَعْنَا لَهُ مَاءً يَتَبَرَّدُ بِهِ فَاغْتَسَلَ ثُمَّ أَتَيْتُهُ بِمِلْحَفَةٍ صَفْرَاءَ فَرَأَيْتُ أَثَرَ الْوَرْسِ عَلَى عُكَنِهِ ‏.‏