Vanaprastha

Vanaprastha, or retired life, is the third spiritual stage (asrama) in the varnasrama system. It lasts from 50 to 75 years of one's life and during this time the vanaprastha ("forest-dweller") lives mainly in forest learning detachment from the material life and preparing himself to accept sannyasa. In the beginning he lives together with his wife. They travel together visiting places of pilgrimage and abstain from sexual relations. Later the wife returns home to be taken care of by her adult sons or enters widows asrama to live a retired life similar to her husband.

SB 3.12.43 lists four stages of vanaprastha: vaikhanasa, valakhilya, audumbara, phenapa, and four stages of sannyasa - kuticaka, bahvoda, hamsa, niskriya.

Aranyakas, one of the four parts of the Vedas (brahmana, samhita, aranyaka, upanisad), are especially meant for vanaprasthas.

Further information: Manu-samhita (ch.6) etc.

Quotes:

"O King, I shall now describe the qualifications for a vanaprastha, one who has retired from family life. By rigidly following the rules and regulations for the vanaprastha, one can easily be elevated to the upper planetary system known as Maharloka."
(SB 7.12.17)

"A person in vanaprastha life should not eat grains grown by tilling of the fields. He should also not eat grains that have grown without tilling of the field but are not fully ripe. Nor should a vanaprastha eat grains cooked in fire. Indeed, he should eat only fruit ripened by the sunshine."
(SB 7.12.18)

"A vanaprastha should prepare cakes to be offered in sacrifice from fruits and grains grown naturally in the forest. When he obtains some new grains, he should give up his old stock of grains."
(SB 7.12.19)

"A vanaprastha should prepare a thatched cottage or take shelter of a cave in a mountain only to keep the sacred fire, but he should personally practice enduring snowfall, wind, fire, rain and the shining of the sun."
(SB 7.12.20)

"The vanaprastha should wear matted locks of hair on his head and let his body hair, nails and moustache grow. He should not cleanse his body of dirt. He should keep a waterpot, deerskin and rod, wear the bark of a tree as a covering, and use garments colored like fire."
(SB 7.12.21)

"Being very thoughtful, a vanaprastha should remain in the forest for twelve years, eight years, four years, two years or at least one year. He should behave in such a way that he will not be disturbed or troubled by too much austerity."
(SB 7.12.22)

"When because of disease or old age one is unable to perform his prescribed duties for advancement in spiritual consciousness or study of the Vedas, he should practice fasting, not taking any food."
(SB 7.12.23)

"The Supreme Personality of Godhead said: One who desires to adopt the third order of life, vanaprastha, should enter the forest with a peaceful mind, leaving his wife with his mature sons, or else taking her along with him."
(SB 11.18.1)

"Having adopted the vanaprastha order of life, one should arrange one's sustenance by eating uncontaminated bulbs, roots and fruits that grow in the forest. One may dress oneself with tree bark, grass, leaves or animal skins."
(SB 11.18.2)

"The vanaprastha should not groom the hair on his head, body or face, should not manicure his nails, should not pass stool and urine at irregular times and should not make a special endeavor for dental hygiene. He should be content to take bath in water three times daily and should sleep on the ground."
(SB 11.18.3)

"Thus engaged as a vanaprastha, one should execute penance during the hottest summer days by subjecting oneself to burning fires on four sides and the blazing sun overhead; during the rainy season one should remain outside, subjecting oneself to torrents of rain; and in the freezing winter one should remain submerged in water up to one's neck."
(SB 11.18.4)

"One may eat foodstuffs prepared with fire, such as grains, or fruits ripened by time. One may grind one's food with mortar and stone or with one's own teeth."
(SB 11.18.5)

"The vanaprastha should personally collect whatever he requires for his bodily maintenance, carefully considering the time, place and his own capacity. He should never collect provisions for the future."
(SB 11.18.6)

"One who has accepted the vanaprastha order of life should perform seasonal sacrifices by offering oblations of caru and sacrificial cakes prepared from rice and other grains found in the forest. The vanaprastha, however, may never offer animal sacrifices to Me, even those sacrifices mentioned in the Vedas.
(SB 11.18.7)

"The vanaprastha should perform the agnihotra, darsa and paurnamasa sacrifices, as he did while in the grhastha-asrama. He should also perform the vows and sacrifices of caturmasya, since all of these rituals are enjoined for the vanaprastha-asrama by expert knowers of the Vedas."
(SB 11.18.8)

"The saintly vanaprastha, practicing severe penances and accepting only the bare necessities of life, becomes so emaciated that he appears to be mere skin and bones. Thus worshiping Me through severe penances, he goes to the Maharloka planet and then directly achieves Me."
(SB 11.18.9)

"One who with long endeavor executes this painful but exalted penance, which awards ultimate liberation, simply to achieve insignificant sense gratification must be considered the greatest fool."
(SB 11.18.10)

"If the vanaprastha is overtaken by old age and because of his trembling body is no longer able to execute his prescribed duties, he should place the sacrificial fire within his heart by meditation. Then, fixing his mind on Me, he should enter into the fire and give up his body."
(SB 11.18.11)

"If the vanaprastha, understanding that even promotion to Brahmaloka is a miserable situation, develops complete detachment from all possible results of fruitive activities, then he may take the sannyasa order of life."
(SB 11.18.12)

"Having worshiped Me according to scriptural injunctions and having given all one's property to the sacrificial priest, one should place the fire sacrifice within oneself. Thus, with the mind completely detached, one should enter the sannyasa order of life."
(SB 11.18.13)

"One in the vanaprastha order of life should always practice taking charity from others, for one is thereby freed from illusion and quickly becomes perfect in spiritual life. Indeed, one who subsists on food grains obtained in such a humble manner purifies his existence."
(SB 11.18.25)