'Ayam vassana kalo' (this is the time to observe 'vas'), and under the 'vinaya' (code of discipline), Buddha made it compulsory for every bhikku, who had received the 'upasampada' (highest ordination), to observe this holy retreat (i.e., retirement to shelter for meditation and rest) for three consecutive months, either beginning from the first day of the waning moon in the month Easala (July), or in the month Nikini (August). The first is known as 'purimika' (pera-vas) and the other is known as 'paccimika' (pasuvas). This year, as there is an additional full moon day in October, the 'peravas'begins in the month Nikini, and the 'pasu-vas' in the month Binara(September). The Buddha has always observed the 'pera-vas' during his 45 years of ministration, wandering from place to place. His exhortation to the bhikkus was: "Anajayami, bhikkhave vassane vassam upagantum" (I declare O bhikkus, to observe the 'vas' during the rainy season). Buddha made it mandatory for the bhikkus to observe the 'vas' during the rainy season whether rains came down or not. He insisted that his disciples should never change the practice depending on rain since he too adhered to the rule without any infringement. Although 'vassana kalo' implies rainy season the period from July to November is reckoned with the outbreak of the South-West monsoonal rains. Even today during the period of the holy retreat ('vas'), the bhikkus are encouraged to meditate, by selecting the subjects of their choice ('kammatthana') while remaining indoors. If for any valid reason or unavoidable circumstances a bhikku observing 'vas' were to leave the place he must return within a week. It is obligatory that he should notifyhis motive in leaving the place to other bhikkus of the temple beforeventuring out. Buddha observed his first 'vas' at the Isipatanaramaya in Saranath (now Benares), after delivering hisfirstdiscourseonDhammacakkappavattana Sutta to the five brahmin ascetice. Soon after came the rains, which prevented him from leaving the hermitage. There after, he observed the 'vas' annually without a breach, at different places, viz: Veluvanaramaya, Katagara hall, Makula pabbata, Thusitha celestial abode, Hesakala forest hermitage, Ghoshitaramaya, Parileyya forest, Ekanala brahmin village, Veranja, Caliya-Pabbata, Jetavanaramaya, Kimbulvatpura, Alaw-rata, Poorvaramaya and Beluwagama.During the rainy season and due to the heavy downpour, many roadsgot submergedinundating the low-lying areas, making the roadsimpassable and dangerous. The ascetice confined themselves in theirhermitages and spent the rainy season in meditation and religiousobservances. But, the disciples of the Buddha, regardless of theunfavourable weather conditions and heavy rain, went from place toplace, in keeping with the exhortation of the Buddha.He said: "Go ye, O bhikkus and wander forth for the gain of the many,for the welfare of the many, in compassion for the world, for the goodfor the gain, for the welfare of gods and men. Proclaim, O bhikkus, theDoctrine glorious, preach ye a life of holiness, perfect and pure". (Mahavagga - Vinaya Pitaka). The disciples thought it best to keep to the word of the Buddha, rather than in wasting their time in solitude. When the bhikkus were in the habit of going from place to place during the rainy season, trampling on grass and insects, the Jain ascetics (followers of Niganta Nataputta alias Vardhamana Mahavira) found fault with the Buddha for allowing his disciples to wander forth carelesslytrampling and killing insects which is taboo to them either directly or indirectly. Thus they raised much hue and cry, and when Buddhabecame aware of their outcry, he advised his disciples too to remainindoors during the rainy season. According to bhikku 'vinaya', the age of an ordained priest is counted from the first 'vas' he observed. He who observes the holy retreat ('vas') for twenty years is considered a Maha Thera. Therefore the observance of 'vas' is an important event in elevating a bhikku to qualifyas a great thera. The 'vas' ends with the 'pavarana' (ritual ending ceremony),which coincides with the 'katina pinkama' or the offering ofnew robes to the bhikku who observed the 'vas'. The cloth which isannually supplied by the laity to the bhikkus, for purpose of makingrobes, is known as 'katina'. Today, robes are generally, not made orstitched, but ready-made ones serve the purpose. The Vinaya Mahavagga mentions that bhikkus should stay within the confines of a predetermined residence, either in his own monastery or as a guest in another place, during the rainy season to observe the 'vas'.In keeping with the injunction, a few bhikkus had left their places ofabode, anticipating to observe the holy retreat with the Buddha whowas staying at the Jetavana monastery. Among them there were bhikkus who had risen to the spiritual eminence of 'sovan' (the first phase of sainthood), of 'sakadagami' (the second phase of sainthood) and 'anagami' (the third phase of sainthood). As they were walking the long distance to the Jetavana monastery, it took more time than they expected to reach their destination. The day on which they should have commenced observing the 'vas' occurred before they met the Buddha. Therefore, in keeping with the 'vinaya' rules, they observed the holy retreat in time at a place some miles away from where the Buddha was staying. The bhikkus were utterly disappointed for what had happened to them. However, they decided to meet the Buddha, after the 'pavarana' (cessation).On their way, heavy rain broke out and they got thoroughly wet. Withthe wet robes they went to meet the Buddha, who seeing their conditionrealised what had happened to them. To overcome such a situation infuture, the Buddha addedanother injunction to the 'vinaya' code thatthey should stay in the same place, where they observed the 'vas', untilthey were offered an additional robe to wear in case of an emergency.The Buddha was happy that the bhikkus did not transgress the rules, even for the sake of meeting the Buddha. The Ariyavamsa Sutta contains the most remarkable feature concerning the life of the bhikku wherein he is expected to preach to the laity, the 'dhamma' (doctrine) of the Buddha, during the 'vas' season. Inthis Sutta, the bhikkus are advised to satisfy themselves with whateveris offered by the laity, in the form of food, clothing and shelter, which heshould receive with a token of delight. The bhikkus most hold their'uposatha' (poya ritual) fortnightly by reciting the 'patimokkha',absolving themselves from any wrongful act done, which is contradictoryto the 'vinaya' rules.Observing 'vas' does not mean that a bhikku should lie in isolationsans human contact, because they are not permitted to observe the holyretreat in desolate places away from human habitation, because theyshould meet the laity and deliver discourses to them to clear the dross of gnorance and show the path leading to Nibbana (the summum bonumof Buddhism).