Siloam Tunnel Inscription - Biblical Archaeology Encyclopedia

Overview

A six-line Hebrew inscription carved into the wall of the rock-cut water channel that carries the Gihon Spring's water under the City of David to the Siloam Pool. It was noticed in 1880 a few metres in from the tunnel's southern end and published by A. H. Sayce in the Palestine Exploration Fund Quarterly Statement in 1881.

The text is a builders' record, not a royal dedication: it describes the last moments of cutting, when two crews tunnelling toward each other could hear each other's voices through the rock, then broke through 'axe against axe', after which the water flowed 1,200 cubits from the spring to the pool, under 100 cubits of rock. No king, date or god is named.

The inscription was hacked out of the wall in 1890, broke into pieces, was recovered by the Ottoman authorities and taken to Constantinople, where it remains in the Istanbul Archaeology Museums. In September 2025 Turkey's president publicly refused Israel's renewed request for its return.

In its own words

The boring through [is completed]. And this is the story of the boring through: while yet [they plied] the drill, each toward his fellow, and while yet there were three cubits to be bored through, there was heard the voice of one calling unto another ... and the waters flowed from the source to the pool for a thousand and two hundred cubits.G. A. Barton, Archaeology and the Bible (Philadelphia: American Sunday-School Union, 1916; 2nd ed. 1917), Part II, ch. 12, p. 377

What the evidence shows

Six lines of Old Hebrew carved on a smoothed patch of the tunnel wall near the Siloam end.
Content: two crews cutting toward each other; 3 cubits left when voices were heard; a 'crevice'/fissure in the rock on the right; breakthrough 'axe against axe'; water flowed 1,200 cubits from spring (motsa) to pool (berekah); 100 cubits of rock overhead (Barton 1917, p. 377).
No king, regnal year, deity or patron is named in the text.
Barton (1917) records the tunnel as 'about 1,700 feet long' after the Parker expedition cleared it (1909-11); the inscription's own figure is 1,200 cubits.
Radiocarbon dates on plant remains in the channel plaster and U-Th dates on speleothems put the tunnel's construction around 700 BCE (Frumkin, Shimron & Rosenbaum 2003).
The stone was cut out of the wall in 1890, breaking it; it has been in Constantinople/Istanbul since (Barton 1917: 'now in the Imperial Ottoman Museum at Constantinople').

Open questions

Who dug it and when. Frumkin, Shimron & Rosenbaum (Nature 425, 2003) date the tunnel to c. 700 BCE from 14C on organic material in the original plaster and U-Th on stalactites, which fits Hezekiah. Reich & Shukron (Tel Aviv 38, 2011) argue completion was at least several decades earlier, in the early 8th century, from pottery in the fills they excavated beside the Gihon Spring, which would mean the tunnel predates Hezekiah. Finkelstein republished a response on 'The Finds from the Rock-Cut Pool in Jerusalem and the Date of the Siloam Tunnel' (2024 collected essays); the chapter's existence is confirmed, but its argument is not summarized here.
Paleography vs. a Hasmonean date. Rogerson & Davies (Biblical Archaeologist 59, 1996) proposed the tunnel and inscription could be 2nd-century BCE; Hendel (Biblical Archaeologist 59, 1996) and Cahill (1997) replied that the letter-forms are Iron Age Hebrew. The later radiometric dates (2003) are consistent with the Iron Age side.
Is 2 Kings 20:20 describing THIS tunnel? The verse credits Hezekiah with 'a pool, and a conduit' bringing water into the city; 2 Chr 32:30 says he 'stopped the upper watercourse of Gihon, and brought it straight down to the west side of the city'. The tunnel runs from the Gihon to a pool on the west side of the City of David, which matches the description; the inscription itself does not name Hezekiah, so the identification rests on the correspondence, not on the text.
The 2025 Siloam Dam dates (805-795 BCE, Regev et al., PNAS 122/35) show that major Gihon-Siloam waterworks already existed c. 800 BCE; they date the dam, not the tunnel, so they do not settle the tunnel's date either way.

Since 2024

2024-08Finkelstein's chapter on the rock-cut pool finds and the date of the Siloam Tunnel appears in his SBL Press collection (verified as published; content not read). [8]
2025-08Radiocarbon dating of the Siloam Dam at the pool to 805-795 BCE (reign of Joash/Amaziah) shows large Gihon-Siloam waterworks c. 800 BCE; it dates the dam, not the tunnel. [7]
2025-09After Netanyahu mentioned his 1998 request for the inscription, President Erdogan said Turkey would not hand it over; it stays in Istanbul. [9]

Sources

A. H. Sayce, 'The Inscription at the Pool of Siloam,' Palestine Exploration Fund Quarterly Statement 13.2 (April 1881): 69-73. DOI 10.1179/peq.1881.13.2.69 link editio princeps
A. H. Sayce, 'The Ancient Hebrew Inscription Discovered at the Pool of Siloam in Jerusalem,' Palestine Exploration Fund Quarterly Statement 13.3 (July 1881): 141-157. DOI 10.1179/peq.1881.13.3.141 link editio princeps
G. A. Barton, Archaeology and the Bible (Philadelphia: American Sunday-School Union, 1916; 2nd ed. 1917), Part II, 'The Siloam Inscription,' p. 377 (Project Gutenberg eBook 43070) link translation
A. Frumkin, A. Shimron & J. Rosenbaum, 'Radiometric dating of the Siloam Tunnel, Jerusalem,' Nature 425 (2003): 169-171. DOI 10.1038/nature01875 link study
R. Reich & E. Shukron, 'The Date of the Siloam Tunnel Reconsidered,' Tel Aviv 38.2 (2011): 147-157. DOI 10.1179/033443511X13099584885268 link study
J. Rogerson & P. R. Davies, 'Was the Siloam Tunnel Built by Hezekiah?' Biblical Archaeologist 59.3 (1996): 138-149, DOI 10.2307/3210545; R. S. Hendel, 'The Date of the Siloam Inscription: A Rejoinder to Rogerson and Davies,' Biblical Archaeologist 59.4 (1996): 233-237, DOI 10.2307/3210565; J. M. Cahill, 'A Rejoinder to "Was the Siloam Tunnel Built by Hezekiah?"', Biblical Archaeologist 60 (1997): 184-185, DOI 10.2307/3210609 link study
J. Regev et al., 'Radiocarbon dating of Jerusalem's Siloam Dam links climate data and major waterworks,' PNAS 122.35 (2025), DOI 10.1073/pnas.2510396122 link study
I. Finkelstein, 'The Finds from the Rock-Cut Pool in Jerusalem and the Date of the Siloam Tunnel,' in Jerusalem the Center of the Universe (SBL Press, 2024), pp. 261-270. DOI 10.2307/jj.17331624.23 link study
'Turkey will never return Siloam Inscription to Israel, Erdogan says,' bianet, 19 Sept 2025 link study

Corrected from the earlier edition of this page

Old entry says R. A. S. Macalister found it in 1880. Barton (1917, p. 377) and the 1881 PEFQS editio princeps by Sayce show it was found in 1880 and published by Sayce; Macalister is not the discoverer.
Old entry says it is 'housed in the Israel Museum'. It is in Istanbul (Barton 1917: 'Imperial Ottoman Museum at Constantinople'; bianet, Sept 2025: Istanbul Archaeology Museum). Only a replica is in Jerusalem.
Old entry says the workers 'met in the middle after eleven months of relentless effort'. The inscription gives no duration and does not say where along the tunnel they met; it gives the total length (1,200 cubits) and the rock height (100 cubits).
Old entry calls it a 'stone slab ... approximately 30 cm long' found in the tunnel. It was carved into the tunnel wall itself and only became a loose slab when it was cut out in 1890.
Old entry quotes '...the tunnel was completed... the workers met...'. The actual text is given above (Barton 1917, p. 377); it names no king.
Old entry lists 'Isaiah 36-37 (Hezekiah's preparations)'. Those chapters narrate the Assyrian envoys and siege, not waterworks; the water passages are 2 Kgs 20:20, 2 Chr 32:3-4, 30 and Isa 22:9-11.
The old summary box asserted 'Authentic 8th century BCE' without evidence; the date is argued from radiometric data (2003) and contested from pottery (2011) and paleography (1996).

Checked against new publications through 2026-09.