ENOfficial
Ibn ‘Abbas said that God's messenger ate a shoulder, and after wiping his hand with a cloth on which he was sitting, he got up and prayed. Abu Dawud and Ibn Majah transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَن ابْن عَبَّاس قَالَ: أَكَلَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَتِفًا ثُمَّ مَسَحَ يَده بِمِسْحٍ كَانَ تَحْتَهُ ثُمَّ قَامَ فَصَلَّى. رَوَاهُ أَبُو دَاوُد وَابْن مَاجَه وَأحمد
sunnah.com