Water of purification
used in cases of ceremonial cleansings at the consecration of
the Levites (Num. 8:7). It signified, figuratively, that
purifying of the heart which must characterize the servants of
God.
Bibliography Information Easton, Matthew George. M.A., D.D., "Definition for 'Water of purification' Eastons Bible Dictionary". bible-history.com - Eastons; 1897.