Narrated Muhayyisah: The Messenger of Allah (ﷺ) said: If you gain a victory over the men of Jews, kill them. So Muhayyisah jumped over Shubaybah, a man of the Jewish merchants. He had close relations with them. He then killed him. At that time Huwayyisah (brother of Muhayyisah) had not embraced Islam. He was older than Muhayyisah. When he killed him, Huwayyisah beat him and said: O enemy of Allah, I swear by Allah, you have a good deal of fat in your belly from his property.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُصَرِّفُ بْنُ عَمْرٍو، حَدَّثَنَا يُونُسُ، قَالَ ابْنُ إِسْحَاقَ حَدَّثَنِي مَوْلًى، لِزَيْدِ بْنِ ثَابِتٍ حَدَّثَتْنِي ابْنَةُ مُحَيِّصَةَ، عَنْ أَبِيهَا، مُحَيِّصَةَ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " مَنْ ظَفِرْتُمْ بِهِ مِنْ رِجَالِ يَهُودَ فَاقْتُلُوهُ " . فَوَثَبَ مُحَيِّصَةُ عَلَى شَبِيبَةَ رَجُلٍ مِنْ تُجَّارِ يَهُودَ كَانَ يُلاَبِسُهُمْ فَقَتَلَهُ وَكَانَ حُوَيِّصَةُ إِذْ ذَاكَ لَمْ يُسْلِمْ وَكَانَ أَسَنَّ مِنْ مُحَيِّصَةَ فَلَمَّا قَتَلَهُ جَعَلَ حُوَيِّصَةُ يَضْرِبُهُ وَيَقُولُ يَا عَدُوَّ اللَّهِ أَمَا وَاللَّهِ لَرُبَّ شَحْمٍ فِي بَطْنِكَ مِنْ مَالِهِ .
sunnah.com