The tradition of the Rains Retreat, or Vassa in Pali, began as a very practical necessity in the time of the Buddha in the physical environment of Northern India. Bikkhus and Bikkhunis, homeless by definition, spent their time going from village to village, at times sleeping out in the elements. The climate of north India has a distinct Monsoon season that takes place from mid-summer to mid-fall. Travel is treacherous during the Monsoon and the risk of harming living beings (including crops, wild animals and themselves) becomes much greater. Therefore the Buddha called for the Vassa to be a time of retreat, devotion to meditation and study, during which Bikkhus and Bikkhunis would be expected to stay in one place for the three-month duration. These ad-hoc gatherings of monks, often in the large homes of wealthy benefactors, actually became the genesis of the first monasteries. The Vassa is still one of the most important times of the year for Theravada monks and nuns. In fact, when members of the Sangha meet for the first time, they may ask one another the question, “How many Rains Retreats have you attended?” to assess which of them is a more senior monk deserving veneration by the other.
The Vinaya Pitaka, or Monastic Code, specifies that there should be two periods offered (beginning a month apart) for the Vassa in order to ensure the participation of all monks (and a second opportunity for those who have broken the first Vassa to actually complete the retreat. While the place of retreat doesn’t have to be a monastery or temple, it should be an actual dwelling place with a door that closes, and it should have at least one Bikkhu that knows how to carry out the rituals related to the full and new moon observances and who are well-versed in the Monastic Code. The monk or nun entering the period of retreat should declare his/her intention, “I am entering this three-month Rains in this dwelling” three times. Once declared, a member of the Sangha may travel away from the retreat site for no more than seven days, but only if called away on clerical or personal business. The Vinaya also makes provisions for hindrances that may arise in travel and other types of obstacles to the successful completion of the Vassa. During the Vassa, the Bikkhus and Bikkhunis are to refrain from taking actions that interfere with the practice of others.
While the Vassa is particularly a time of devotion and deep practice for the Sangha, it is also a time for laypeople to take practice more seriously and to practice dana (generosity) sila (virtue) and bhavana (meditation). Laypeople may practice an increased number of training precepts, or choose to work on a particular area of attachment during this period. This is perhaps why in western cultures, Vassa may be considered to be the “Buddhist Lent”.
This special time of year requires special rules, but with successful completion also confers special benefits to the Bikkhus and Bikkhunis.
One benefit that takes place in the month following the Rains Retreat is the Kathina Ceremony, when monks receive new robes (acknowledging the likely wear and tear on the Sangha’s robes that results from extreme Monsoon weather). In ancient times, gifts of cloth were given to the entire Sangha, to be distributed by appointed monks. In modern times, the Kathina Ceremony is an auspicious time to provide members of the Sangha with not only robes but other useful requisites and supplies. These are not personal gifts, but instead they are symbolically offered to the entire Sangha of Bikkhus and Bikkhunis, past, present and future, thereby accruing the highest amount of merit for the givers of this dana.