Jami` at-Tirmidhi 1506
جامع الترمذي#1506Da'ifحَدَّثَنَا أَحْمَدُ بْنُ مَنِيعٍ، حَدَّثَنَا هُشَيْمٌ، أَخْبَرَنَا حَجَّاجُ بْنُ أَرْطَاةَ، عَنْ جَبَلَةَ بْنِ سُحَيْمٍ، أَنَّ رَجُلاً، سَأَلَ ابْنَ عُمَرَ عَنِ الأُضْحِيَةِ، أَوَاجِبَةٌ هِيَ فَقَالَ ضَحَّى رَسُولُ اللَّهِ صلى الله عليه وسلم وَالْمُسْلِمُونَ . فَأَعَادَهَا عَلَيْهِ فَقَالَ أَتَعْقِلُ ضَحَّى رَسُولُ اللَّهِ صلى الله عليه وسلم وَالْمُسْلِمُونَ . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ . وَالْعَمَلُ عَلَى هَذَا عِنْدَ أَهْلِ الْعِلْمِ أَنَّ الأُضْحِيَةَ لَيْسَتْ بِوَاجِبَةٍ وَلَكِنَّهَا سُنَّةٌ مِنْ سُنَنِ رَسُولِ اللَّهِ صلى الله عليه وسلم يُسْتَحَبُّ أَنْ يُعْمَلَ بِهَا وَهُوَ قَوْلُ سُفْيَانَ الثَّوْرِيِّ وَابْنِ الْمُبَارَكِ .
Narrated Jabalah bin Suhaim :That a man asked Ibn 'Umar about the Udhiyah, "Is it obligatory?" So he said: "The Messenger of Allah (ﷺ) performed the Udhiyah as did the Muslims." He repeated the question. So he said: "Do you understand ?" The Messenger of Allah (ﷺ) slaughtered as did the Muslims
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 19:17