Majma al-Zawaid — Hadith 18100

Sayyidah Umm Abdullah (may Allah be pleased with her), the sister of Sayyiduna Shaddad bin Aws (may Allah be pleased with him), sent a cup of milk to the Prophet (peace and blessings be upon him) at the time of breaking the fast. The Prophet (peace and blessings be upon him) was fasting, and it was a long and intensely hot day. The Prophet (peace and blessings be upon him) sent the woman's messenger back to her and asked: "Where did you get this milk from?" The woman said: "It is from my goat." The Prophet (peace and blessings be upon him) sent the messenger back to the woman and said: "Where did you get this goat from?" The woman said: "I bought it with my own money." So the Prophet (peace and blessings be upon him) accepted that milk. The next day the woman came to the Prophet (peace and blessings be upon him), and Sayyidah Umm Abdullah (may Allah be pleased with her) said: "O Messenger of Allah! I sent milk to you because the day was long and intensely hot, and you sent back the person I had sent?" The Prophet (peace and blessings be upon him) said to the woman: "The Messengers were commanded with this very thing: that they eat only what is pure and do only righteous deeds."
Al-Tabarani recorded it; its chain contains a narrator, Abu Bakr bin Abi Maryam, who is da'if (weak).