This was a prescribed part of the Jewish ritual of purification in cases of accident, or of leprous or ordinary uncleanness, (Leviticus 15; 16:28; 22:6; Numbers 19:7; 19; 2 Samuel 11:2,4; 2 Kings 5:10) as also after mourning, which always implied defilement. (Ruth 3:3; 2 Samuel 12:20) The eastern climate made bathing essential alike to health and pleasure, to which luxury added the use of perfumes. (Esther 2:12) Judith 10:3; Susan 17, and you can find more about that here on st-takla.org on other commentaries and dictionary entries. The "pools," such as that of Siloam and Hezekiah, (2 Kings 20:20; Nehemiah 3:15,16; Isaiah 22:11; John 9:7) often sheltered by porticos, (John 5:2) are the first indications we have of public bathing accommodation.
Main reference: Smith's Bible Dictionary (1860s)
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