If you buy a liter of olive oil, you’ll likely want to ensure you’re getting your money’s worth. And if you’re selling a liter of olive oil, you want to be paid fairly for it. Ancient residents of what is now East Jerusalem had the same problem. They relied on the market’s inspector of measurements and weights, the agoranomos, to ensure all was fair.

Archaeologists excavating a large underground square recently unearthed tools of the agoranomos’ trade, according to a statement released Monday by the Israel Antiquities Authorities. The most notable specimen is a small stone table with vertical cavities that resemble cup holders. Used to calibrate sellers’ vessels for selling liquids such as wine and oil, the measuring table is only the third of its kind found to date in the Jerusalem area.

As Ruth Schuster explains for Haaretz, each cavity had a known volume. To dispense the proper amount of liquid, the measurements inspector would use their finger to plug a hole at the bottom of a cavity, then fill the stone tool with water. Once a buyer had placed their vessel under the hole, the inspector would release their finger. After the buyer’s vessel was filled with water, the seller marked the liquid level, confirming the agreed-upon volume for the actual purchase.

“In my childhood we would buy milk this way,” University of Haifa archaeologist and excavation director Ronny Reich tells Schuster.

The Romans began constructing “Pilgrimage Road,” where the square is situated, in 20 A.D. The market hub remained in use until 70 A.D., when occupying Roman armies destroyed the area to quell a rebellion. The street was once lined with two-story shops on both sides, IAA archaeologist Ari Levy tells Amanda Borschel-Dan at the Times of Israel.

Although the square is now 16 feet underground, the discovery of the measuring table, as well as dozens of weights, suggests it was a center of commerce for pilgrims during the Second Temple Period. Per the IAA statement, the measuring weights followed a system unique to Jerusalem, testifying to the city’s strong economy and trade networks.

The main stretch of Pilgrimage Road was first uncovered in 2009. The pathway spans 600 meters, starting at the first Pool of Siloam, a stone-cut freshwater reservoir unearthed in 2005, and ending at the Temple.

“There is practically no doubt that this was the focus of pilgrim traffic. We know this both from Jewish and Christian sources,” Reich told Haaretz’s Nir Hasson at the time. “The Pool of Siloam provided water for hundreds of people simultaneously and could be used for purification before ascending to the Temple Mount.”

It stands to reason that salespeople would want to set up shop in a high-traffic area like the road to the temple. The city’s usual population of 25,000, already a bustling metropolis for the era, could double during pilgrimage festivals. With so much merchant activity taking place, the agoranomos’ office would probably need to be stationed nearby.