The Rivers Of Living Water (John 7:37-44).
Meanwhile the Feast of Tabernacles was drawing to a close with its emphasis on harvest and the prayers for rain for the coming year. The people were totally dependent on that rain for survival, and during the seven days of this feast a ceremonial procession would gather water each day from the pool of Siloam and carry it to the Temple. There it was poured out before God at the time of the morning sacrifice while the people chanted the words of Isaiah 12:3 - ‘with joy you will draw water from the wells of deliverance'. It was their cry for rain in the coming season.
But it also looked forward to the great expected time of deliverance, that time when God would step in and deliver His people from their oppressors, the time when the land would flourish as it never had before, seeing rain in abundance (Isaiah 32:15) and great flowing rivers (Joel 3:18; Ezekiel 47:1-12; Zechariah 14:8), and when the pouring out of the Spirit would produce fruitfulness of another kind in the hearts of men (Isaiah 44:1-4; Joel 2:23-29). It was a time of high excitement. The people were ever filled with an expectancy that God would act. And what was happening about Jesus had added to that excitement.
The detailed celebration of the Feast was as follows. Early on each of the seven mornings of the feast the high priest would lead a procession from the Pool of Siloam to the temple. Another priest, again accompanied by crowds, would at the same time fill a golden ewer with water from the pool. He would then carry it through the Water Gate on the south side of the temple and into the temple courtyard. There he would ceremoniously pour the water into a silver basin on the west side of the brazen altar from which it would flow through a tube to the base of the altar.
Many Jews would accompany these priests. Some of them would drink from the pool while others would chant Isaiah 55:1; Isaiah 12:3: "Ho! Everyone who thirsts, come to the waters -- with joy draw water from the springs of salvation." This was such a happy occasion that the Mishnah stated, "He who has never seen the joy of the water-drawing has never in his life seen joy." (Sukkoth John 5:1). The priest would then pour water into the basin at the time of the morning sacrifice. Another priest would also pour the daily drink offering of wine into another basin at the same time. Then they would pour the water and the wine out before the Lord.
The pouring out of water represented God's past provision of water in the wilderness and His provision of refreshment in the future times of the Messiah. The pouring out of wine symbolised God's bestowal of His Spirit in the days to come. Every male present would simultaneously shake his small bundle of willow and myrtle twigs (his lulab) with his right hand and hold a piece of citrus fruit aloft with his left hand. The twigs represented stages of the wilderness journey marked by different kinds of vegetation, and the citrus fruit symbolised the fruit of the Promised Land. Everyone would also cry, "Give thanks to the Lord!" three times. Worshippers in the temple courtyard would then sing the Hallel (Psalms 113-118). So by the end of the seven days excitement was at its peak, and all were thinking of the future work of God's Spirit. This would be followed by the eighth day, possibly ‘the great day of the feast'.
Whether in fact the ‘great day of the feast, was the seventh day or the eighth day is disputed. The seventh day was a festal sabbath, and while during the first six days the priests walked once round the altar, on the seventh day they walked round it seven times. Thus it was seen as an important day. But the feast had come to be seen as one of eight days so that ‘the last day' would naturally be interpreted as the eighth day.