On this seventh and last day of the Feast of Tabernacles, as many of you know, ancient Israel had a custom that was completed on this day in this priestly ritual of pouring water from the pool of Siloam upon the altar.
During this period, expectation for the coming Messiah intensified and also became misconstrued with political division. This is important when we consider this ritual and the politics of the time and the Jewish expectations that had been corrupted over the Intertestamental period.
Each day of the Feast, a priest would draw water from the pool of Siloam, using a golden pitcher, and carry it through the Water Gate to the Temple, accompanied by recitations from the prophets and hymns of praise.
On the last day of the Feast, the great day, the procession circled the altar seven times before pouring water, creating a vapor that symbolized God's presence filling the Temple.
Brethren, despite the worn conditions of the temporary dwellings by this seventh day of the Feast of Tabernacles, which was mentioned earlier in the Feast, the inspired writing of the apostle John makes sure we know this is a great day. As a matter of fact, it is the greatest day of the Feast.
Please note what precedes Christ's declaration in John 7:37 and what immediately follows contained God's inspired brackets concerning what He thought about this day and why. This is something that was not clearly seen by the physical people to whom these words were spoken because their focus on God's Word had been so politically distorted over the centuries that they could not see the Word of God who was in their very midst.
Brethren, to physical Israel, that had been divorced because of their harlotry, all Christ's words only caused division and contention as we see throughout the Feast of Tabernacle's chapter.