Mahabharata Anushasna Parva Chapter 107:2

Mahabharata Anushasna Parva (Dana Dharma Parva) Chapter 107:2 That man who eats only one meal every third day, and pours libations every day on his sacred fire for a period of a whole year,—indeed, he who thus attends to his fire every day and wakes up from sleep every morning before the sun is up, attains to the high merit of the Atiratra sacrifice. He acquires a car drawn by peacocks and swans and cranes. Proceeding to the region of the seven (celestial) Rishis, he takes up his residence there, surrounded by Apsaras of great beauty. It is well-known that such residence lasts for full three Padmas of years.[] Fasting for three days in succession, he who takes only one meal every fourth day, and pours libations every day on his sacred fire, acquires the high merit of the Vajapeya sacrifice. The car he acquires is graced by celestial damsels of great beauty that have Indra for their father. He resides in the region of Indra for millions and millions of years and experiences great happiness by witnessing the sports of the chief of the deities. Fasting for four days in succession, he who eats only one meal every fifth day, and pours libations on the sacred fire every day for the period of a whole year, and who lives without cupidity, telling the truth, reverencing the Brahmanas, abstaining from every kind of injury, and avoiding malice and sin, acquires the merit of the Vajapeya sacrifice. The car he rides is made of gold and drawn by swans and endued with the effulgence of many suns rising together. He acquires a palatial mansion of pure white. He lives there in great happiness for full one and fifty Padmas of years.[] Fasting for five days, he who takes food on only the sixth day, and pours libations on his sacred fire every day for a whole year, and who performs three ablutions in course of the day for purifying himself and saying his prayers and doing his worship, and who leads a life of Brahmacharya, divested of malice in his conduct, acquires the merit of the Gomedha sacrifice. He acquires an excellent car adorned with pure gold, possessed of the effulgence of a blazing fire and drawn by swans and peacocks. He sleeps on the lap of Apsaras and is awakened every morning by the melodious tinkle of Nupuras and Kanchis. He leads such a life of happiness for ten thousand million years and three thousand million besides and eight and ten Padmas and two Patakas.[] Such a man resides also, honoured by all, in the region of Brahma for as many years as there are hairs on the bodies of hundreds of bears. Fasting for six days, he who eats only one meal every seventh day and pours libations on the sacred fire every day, for a full year, restraining speech all the while and observing the vow of Brahmacharya, and abstaining from the use of flowers and unguents and honey and meat, attains to the region of the Maruts and of Indra. Crowned with the fruition of every desire as it springs up in the mind, he is waited upon and adored by celestial damsels.