Thoughts on Mezigah
The pouring of the water on the chag is mixing the water into the wine that is poured onto the mizbeach. This correponds to the mixing of water and wine at meal since a persons table is a mizbeach. Their is always only joy at a meal (like on the chag) corresponding with the All-mighty's kindess in giving food to all with out regard to the receivers merit. (on the chag as well, offerings were brought for all nations, regardless of merit.) Tolat Yakov