John 7:37

The last day] The feast proper closed on the seventh day, but the eighth day, which is probably here meant, was kept as a sabbath with a holy convocation to commemorate the entrance into Canaan (Leviticus 23:36). If any man thirst] Here, as to the woman of Samaria, Christ declares Himself the giver of 'the living water.' This declaration is connected with the ritual of the feast. On every day of the feast except the last, a golden pitcher of water was fetched (in literal fulfilment of Isaiah 12:3) from the pool of Siloam by a priest, and poured together with wine on the W. side of the altar at the time of the morning sacrifice, amid the singing of psalms and hymns. This water was held to symbolise the miraculous water which supplied the Israelites in the wilderness, and also the outpouring of the Spirit promised in the days of the Messiah. On the eighth day, when the water was not poured out, Jesus came forward declaring Himself the giver of the true water which that water typified, viz. the Holy Spirit.