Sunan Ibn Majah, Volume 5, Book 37, Hadith 4273 (DarusSalam) ⓘ
It was narrated from Abu Sa’eed that the Messenger of Allah said: “The two who are entrusted with the Trumpet have two horns in their hands, waiting until they will be commanded (to blow them).”
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَبَّادُ بْنُ الْعَوَّامِ، عَنْ حَجَّاجٍ، عَنْ عَطِيَّةَ، عَنْ أَبِي سَعِيدٍ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " إِنَّ صَاحِبَىِ الصُّورِ بِأَيْدِيهِمَا - أَوْ فِي أَيْدِيهِمَا - قَرْنَانِ يُلاَحِظَانِ النَّظَرَ مَتَى يُؤْمَرَانِ " .
also referenced under: Hadith 4273 (Reference) & Book 37, Hadith 4414 (In-Book)