ENOfficial
Samura b. Jundub said God’s messenger used to order them to deduct the sadaqa from what they prepared for trade. Abu Dawud transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ سَمُرَةَ بْنِ جُنْدُبٍ: أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ يَأْمُرُنَا أَنْ نُخْرِجَ الصَّدَقَةَ مِنَ الَّذِي نُعِدُّ لِلْبَيْعِ. رَوَاهُ أَبُو دَاوُد
sunnah.com