'Abdullah told him that the Messenger of Allah used to offer the sacrifice at the prayer place.  

أَخْبَرَهُ أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يَذْبَحُ أَوْ يَنْحَرُ بِالْمُصَلَّى  

the Messenger of Allah offered the sacrifice obn the Day of Sacrifice in Al-Madinah. He said: "if he did not offer the Nahr (sacrifice a camel) he would have offered Dhabihah (Sacrificed a sheep) at the prayer place."  

أَنَّ رَسُولَ اللَّهِ ﷺ نَحَرَ يَوْمَ الأَضْحَى بِالْمَدِينَةِ قَالَ وَقَدْ كَانَ إِذَا لَمْ يَنْحَرْ يَذْبَحُ بِالْمُصَلَّى