John 7:37 - Clarke's commentary and critical notes on the Bible

In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink. In the last day, that great day of the feast - This was the eighth day, and was called the great day, because of certain traditional observances, and not on account of any excellence which it derived from the original institution. On the seven days they professed to offer sacrifices for the seventy nations of the earth, but on the eighth day they offered sacrifices for Israel; therefore the eighth day was more highly esteemed than any of the others. It is probably to this that the evangelist refers when he calls the last day the great day of the feast. See the account of the feast of tabernacles, in the note on John 7:2 (note). It was probably when they went to draw water from the pool Siloam, and while they were pouring it out at the foot of the altar, that our Lord spoke these words; for, as that ceremony pointed out the gracious influences of the Holy Spirit, our Lord, who was the fountain whence it was to proceed, called the people to himself, that, by believing on him, they might be made partakers of that inestimable benefit.