We have seen that water baptism, was part of the Mosaic Law and there is further prove. We are going to be looking at two pools that the Jews used to water baptize Siloam and Bethesda. For Jews it was not a new concept, they had constructed pools designated for the ceremony of water baptism. Archeologist have found parts of these pools, they have discovered that these pools were not just symbolic inventions of the authors in the bible, they actually did exist, very close to the descriptions given in the bible. Here are some of the biblical references to the pools Siloam and Bethesda:
2 Chronicles 32:30; 2 Kings 18:17; 2 Kings 20:20; Nehemiah 3:15; Isaiah 7:3; Isaiah 8:6-7; Isaiah 22:9-11; Isaiah 36:2; John 5:1-9; John 9:7-11
From the accounts in John we can also see that this pools were not limited only to the priest they were open to the public (John 5:3 and John 9:7). Water baptism was a very important part of the Jewish Law, that they had facilities for the practice of these ceremonies in ancient times.
I will not be going into the details of the pools but if you want to learn more here is a link: http://www.sacred-destinations.com/israel/jerusalem-pool-of-siloam.htm