This excerpt is taken from Sheikh Abu Hamza Abdul Khaliq Siddiqi's book Sahi Fazail-e-Amaal.
It is narrated from Sayyiduna Zaid bin Khalid Al-Juhani, may Allah be pleased with him, that the Prophet Muhammad, peace be upon him, said: "Whoever provides iftar for a fasting person will receive a reward equal to that of the fasting person, without any reduction in the reward of the fasting person."
Reference: Sunan Tirmidhi, Book of Fasting, Chapter on the Virtue of Providing Iftar to a Fasting Person. Sahih Ibn Khuzaymah: 277/3.
Ibn Khuzaymah has declared it "Sahih."It is narrated from Umm Amarah Al-Ansariyyah, may Allah be pleased with her, that the Prophet Muhammad ﷺ came to her. She presented food. The Prophet ﷺ said, "Then eat." She said, "I am fasting." The Messenger of Allah ﷺ said: "If food is eaten in the presence of a fasting person, the angels continue to pray for mercy for him until they finish, or perhaps the Prophet ﷺ said, until he is satisfied (they continue to pray for mercy)."
Reference: Sunan Tirmidhi, Book of Fasting, Chapter on the Virtue of Fasting. Sahih Ibn Khuzaymah: 307/3. Sahih Ibn Hibban (Al-Ihsan): 181/5 -
Ibn Hibban and Ibn Khuzaymah have declared it "Sahih."