Sahih Muslim Book - 35, Hadith - 5069

وحَدَّثَنَا يَحْيَى بْنُ يَحْيَى ، أَخْبَرَنَا خَالِدُ بْنُ عَبْدِ اللهِ ، عَنْ مُطَرِّفٍ ، عَنْ عَامِرٍ ، عَنِ الْبَرَاءِ ، قَالَ : ضَحَّى خَالِي أَبُو بُرْدَةَ قَبْلَ الصَّلاَةِ ، فَقَالَ رَسُولُ اللهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: تِلْكَ شَاةُ لَحْمٍ ، فَقَالَ: يَا رَسُولَ اللهِ ، إِنَّ عِنْدِي جَذَعَةً مِنَ الْمَعْزِ ، فَقَالَ: ضَحِّ بِهَا ، وَلاَ تَصْلُحُ لِغَيْرِكَ ، ثُمَّ قَالَ: مَنْ ضَحَّى قَبْلَ الصَّلاَةِ ، فَإِنَّمَا ذَبَحَ لِنَفْسِهِ ، وَمَنْ ذَبَحَ بَعْدَ الصَّلاَةِ فَقَدْ تَمَّ نُسُكُهُ ، وَأَصَابَ سُنَّةَ الْمُسْلِمِينَ.

It was narrated that Al-Bara' said: "My maternal uncle Abu Burdah offered his sacrifice before the prayer, and the Messenger of Allah (s.a.w) said: 'That is just a sheep for meat.' He said: 'O Messenger of Allah, I have a Jadh'ah goat.' He said: 'Offer it as a sacrifice, but that will not suffice for anyone but you.' Then he said: 'Whoever offered the sacrifice before the prayer has only slaughtered it for himself, but whoever offers the sacrifice after the prayer has completed his rituals and done it according to the Sunnah of the Muslims."'