That the Messenger of Allah ﷺ said: "A human does no action from the actions on the day of Nahr more beloved to Allah then spilling blood (of sacrificial animals). On the Day of Judgement, it will appear with its horns, and hair, and hooves, and indeed the blood will be accepted by Allah from where it is received before it even falls upon earth, so let your heart delight in it."  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ مَا عَمِلَ آدَمِيٌّ مِنْ عَمَلٍ يَوْمَ النَّحْرِ أَحَبَّ إِلَى اللَّهِ مِنْ إِهْرَاقِ الدَّمِ إِنَّهَا لَتَأْتِي يَوْمَ الْقِيَامَةِ بِقُرُونِهَا وَأَشْعَارِهَا وَأَظْلاَفِهَا وَإِنَّ الدَّمَ لَيَقَعُ مِنَ اللَّهِ بِمَكَانٍ قَبْلَ أَنْ يَقَعَ مِنَ الأَرْضِ فَطِيبُوا بِهَا نَفْسًا قَالَ وَفِي الْبَابِ عَنْ عِمْرَانَ بْنِ حُصَيْنٍ وَزَيْدِ بْنِ أَرْقَمَ