Musannaf Ibn Abi Shaybah

Hazrat Umm Hani states that I was sitting with the Noble Prophet (peace and blessings be upon him). Something to drink was brought to him, which he drank. He gave it to me, and I also drank from it. Then I said, "O Messenger of Allah! I have committed a sin, please seek forgiveness for me." He asked, "What sin have you committed?" I said, "I was fasting and I broke my fast." He said, "Were you making up a missed fast?" I replied, "No." The Prophet (peace and blessings be upon him) said, "There is no harm for you in this."

Hazrat Ikrimah states that Ibn Abbas (may Allah be pleased with them) used to break a voluntary fast and did not mind it.

Hazrat Yusuf bin Mahak Makki says that Hazrat Abdullah bin Abbas (may Allah be pleased with them) had intercourse with one of his slave women while he was fasting. Someone said to him, "You have had intercourse with her while fasting?" He replied, "She was my slave woman, I liked her. Besides, the fast was voluntary (nafl)."

Hazrat Sha'bi did not consider it objectionable for a person to break a voluntary fast.

Hazrat Aisha (may Allah be pleased with her) narrates that sometimes a fine and rare thing would be gifted to us. We would say to the Messenger of Allah (peace and blessings be upon him) that if you were not fasting, we would have presented this to you. He would have that thing brought and we would break our fast with it.

Hazrat Abu Miskeen says that Ibrahim and Hazrat Saeed bin Jubair were at a feast. Hazrat Saeed said that he had mentioned fasting. Then he ate, and Ibrahim said that he did not like this.

Ibrahim says that if someone makes the intention to fast, then he should not break the fast.