Mishkat al-Masabih 4336
Mu'awiya b. Qurra quoted his father as saying:
I came to the Prophet with a company of Muzaina who swore allegiance to him, and as his buttons were open I put my hand inside his shirt and felt the seal.
Abu Dawud transmitted it.
وَعَنْ مُعَاوِيَةَ بْنِ قُرَّةَ عَنْ أَبِيهِ قَالَ: أَتَيْتُ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي رَهْطٍ مِنْ مُزَيْنَةَ فَبَايَعُوهُ وَإِنَّهُ لَمُطْلَقُ الْأَزْرَارِ فَأَدْخَلْتُ يَدِي فِي جَيْبِ قَمِيصِهِ فَمَسِسْتُ الْخَاتم. رَوَاهُ أَبُو دَاوُد