‘Drawing water’ is a translation for the Japanese mizu tori, itself a reference to the O-mizu tori ceremony carried out at the Nigatsudō in the Tôdaiji temple in Nara.
O-mizu tori is an alternative name for the Shûni-e 修二会 ceremonies carried out between the first and fourteenth days of the Second Month of the lunar calendar (currently performed from the 1st to 15th of March), for purification and the protection of the nation. This one of the oldest rites in Japan, having been performed without fail for the past 1250 years.
The ceremony has its origins in 751, when a monk by the name of Jitchū 実忠 went on a retreat in the Kasagi 笠置 mountains east of Nara. There, he observed a group of Bodhisattvas performing a ceremony for Kannon, and petitioned them to allow him to transfer the rite to the world of men. They warned him that a single day of ritual in Heaven was equivalent to 400 years of ritual on Earth, so he conceived the idea of performing a ritual 1000 times a day at running speed in compensation.
The Shūni-e itself is performed by eleven specially selected priests, who purify themselves in preparation during February and then conduct various observances and practices in the Nigatsudō during the first half of March. These include Hashiri no Gyōbō 走りの行法, the ‘Running Rite’, which involves running in a circuit around the Nigatsudō in order to catch up with Heaven.
The climax of the ceremony is the O-mizu tori rite, which occurs on March 13th. According to legend, Jitchû once invited 13,700 deities to attend his ritual, one of whom, Onyūmyōjin 遠敷明神, a deity from the province of Wakasa 若狭, was late as he had been fishing. By way of apology, he caused two cormorants, one black and one white, to fly up from a rock creating a spring of sacred scented water, or kôsui 香水 to be used in the ritual. In the O-mizu tori ceremony, water is drawn from this sacred Wakasa Spring 若狭井, which lies beneath the Nigatsudô, and placed in two vessels. One contains water drawn during all the previous rituals, and one water from the previous year; some of the water from the first vessel is also added to the second. Subsequently, more water is drawn from the spring, some for use as an offering to the image of Kannon in the temple, and some to be given away to attendees at the ceremony for use in their own offerings throughout the year. Meanwhile, outside the temple, eleven great basket-torches or taimatsu 松明 are lit and swung to send sparks raining down upon the crowds attending the ceremony.
More detailed information on O-mizu tori can be found here.
While the Shūni-e was one of the main official signifiers of the beginning of Spring, it was frequently icy cold when it was performed, hence Bashō’s reference to the monks’ shoes being ice-covered, and the noise they make as their owners circulate around the Nigatsudô performing the Hashiri no Gyōbō.