John 2:6 - Ellicott's Commentary On The Whole Bible

Waterpots, or pitchers, like to but larger than the vessels used for carrying water, as in John 4:28. These were placed in the outer court, away from the guest-chamber, for the governor of the feast is ignorant of the circumstances (John 2:9). It is natural that an eyewitness should remember the number and know roughly their size. There were six of them, containing about twenty gallons apiece; but hidden meanings referring to the number or the quantity are brought to the text, not derived from it. The measure rendered “firkin” is metretes, which is used for the Hebrew, “bath” in 2 Chronicles 4:5. This (Jos. Ant. viii. 2, § 9) gives nearly nine gallons as the value of the “firkin,” which multiplied by two or three gives the contents of each pitcher as from about eighteen to twenty-seven gallons; or, approximately, from 100 to 150 gallons for the whole. Our own word “firkin” is probably “a little fourth,” and equal to nine gallons, or the fourth of a barrel (comp. Tierce, which is one-third). It is used only here in the Bible.