Sahih Muslim 1961dBook 35, Hadith 9
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ نُمَيْرٍ، ح وَحَدَّثَنَا ابْنُ نُمَيْرٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا زَكَرِيَّاءُ، عَنْ فِرَاسٍ، عَنْ عَامِرٍ، عَنِ الْبَرَاءِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ صَلَّى صَلاَتَنَا وَوَجَّهَ قِبْلَتَنَا وَنَسَكَ نُسُكَنَا فَلاَ يَذْبَحْ حَتَّى يُصَلِّيَ " . فَقَالَ خَالِي يَا رَسُولَ اللَّهِ قَدْ نَسَكْتُ عَنِ ابْنٍ لِي . فَقَالَ " ذَاكَ شَىْءٌ عَجَّلْتَهُ لأَهْلِكَ " . فَقَالَ إِنَّ عِنْدِي شَاةً خَيْرٌ مِنْ شَاتَيْنِ قَالَ " ضَحِّ بِهَا فَإِنَّهَا خَيْرُ نَسِيكَةٍ " .
He who observes prayer like our prayer and turns his face towards our Qibla (in prayer) and who offers sacrifices (of animals) as we do, he must not slaughter the (animal as a sacrifice) until he has completed the prayer. Thereupon my maternal uncle said: Messenger of Allah, I have sacrificed the animal on behalf of my son. The Messenger of Allah (ﷺ) said: This is the thing in which you have made haste for your family. He said: I have a goat with me better than two goats. Thereupon he said: Sacrifice it for that is the best.