Wills (Kitab Al-Wasaya)
Dawud :: Book 17 : Hadith 2865
Narrated Abdullah ibn Abbas:
When Allah, Most High, revealed the verses: "Come not nigh to the orphan's property except to improve it". And "Those who unjustly eat up the property of orphans", everyone who had an orphan with him went and separated his food from his (orphan's) food, and his drink from his drink, and began to detain the remaining food which he (the orphan) himself ate or spoiled.
This fell heavy on them, and they mentioned this to the Apostle of Allah (peace_be_upon_him). So Allah, Most High, revealed the verse: "They ask thee concerning orphans. Say: The best thing to do is what is for their good; if ye mix their affairs with yours, they are your brethren." Then they mixed their food with his food and their drink with his drink.