The Messenger of Allah (May peace be upon him) came upon a date on the road; he would not take it for fear of being a part of the sadaqah. (Using translation from Abū Dāʾūd 1651)
«أَنَّ النَّبِيَّ ﷺ كَانَ يَمُرُّ بِالتَّمْرَةِ سَاقِطَةً فَلَا يَمْنَعُهُ مِنْ أَخْذِهَا إِلَّا مَخَافَةُ الصَّدَقَةِ»