Perpetual fasting

Sayyiduna Abu Malik al-Ash'ari (may Allah be pleased with him) narrated: The Prophet (peace and blessings be upon him) said: "Indeed, in Paradise there are upper chambers whose outside can be seen from the inside and whose inside can be seen from the outside. Allah Almighty has prepared them for the one who feeds others, speaks gently, fasts continually, and offers voluntary prayer when people are asleep."
Imam Ahmad recorded it, and its narrators are thiqat (trustworthy). This hadith has various routes which will be mentioned in their proper places, if Allah wills.

Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "Whoever fasts perpetually, Hell will be constricted upon him like this." The Prophet (peace and blessings be upon him) said this while closing his fist.
Imam Ahmad and Imam al-Bazzar recorded it; however, he (al-Bazzar) reported the wording: "The Prophet (peace and blessings be upon him) said this while forming (with his fingers) the sign of ninety."
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators are the narrators of the Sahih.

Abu Qays, the freed slave of Amr, narrated: Sayyiduna Amr (may Allah be pleased with him) used to keep voluntary fasts continuously.
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators are the narrators of the Sahih.

Mujahid narrated: Yahya bin Ja'dah and I went to a Companion from the Ansar. He narrated: A freed slave woman of Banu Abd al-Muttalib was mentioned before the Prophet (peace and blessings be upon him), and the speaker said: "She spends the whole night in voluntary prayer and fasts during the day." The Prophet (peace and blessings be upon him) said: "But I sleep (at night) and I also pray, and I also leave (voluntary) fasting. Whoever follows me is from me, and whoever turns away from my Sunnah has nothing to do with me. Every deed has a period of zeal, then slackness comes into it. Whoever's slackness leads to innovation (bid'ah) has gone astray, and whoever's slackness leads to my Sunnah has been guided."
Imam Ahmad recorded it, and its narrators are the narrators of the Sahih. Some hadiths similar to this have already passed.

Sayyidah Asma' bint Yazid (may Allah be pleased with her) narrated: A drink was brought to the Prophet (peace and blessings be upon him), and the drink was passed round to all those present. Among them was a man who was fasting. When the drink reached him, the Prophet (peace and blessings be upon him) said to him: "Drink!" It was said: "O Messenger of Allah! This man does not leave any voluntary fast; he fasts continually." The Prophet (peace and blessings be upon him) said: "The one who fasts perpetually has not in reality fasted."
Imam Ahmad and Imam al-Tabarani in al-Mu'jam al-Kabir recorded it, and he (al-Tabarani) reported the wording: "Whoever fasts perpetually has neither fasted nor broken his fast." Its chain contains a narrator, Layth bin Abi Sulaym; he is thiqah (trustworthy), but he is a mudallis (one who conceals defects in the chain).

Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) reports this saying of the Prophet (peace and blessings be upon him): "The one who fasts (voluntary fasts) perpetually has not fasted."
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir. Its chain contains a narrator, Ubaydah bin Mu'attib, and he is matruk (abandoned).

Sayyiduna Abdullah bin Sufyan (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "The one who fasts (voluntary fasts) perpetually has not fasted."
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir. Its chain contains a narrator, Muhammad bin Abi Layla, about whom criticism has been made.

Amr bin Salimah narrated: Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) was asked about fasting perpetually, and he disliked it and said: "Three (voluntary) fasts should be kept in every month."
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir, and its chain is hasan (good).