Tobiads in the Lachish ostraca
The Lachish ostraca are a collection of approximately twenty inscribed potsherds, discovered in 1935 and 1938 in Tell ed-Duweir, located in the maritime plain of Israel, identified with the ancient city of Lachish. At one time Lachish was the second most important city of the kingdom of Judah. Lachish was devastated by the Assyrians. It remained unoccupied until the time of Nehemiah when he says it had a "remnant of Israel." Excavation at Lachish revealed a set of ostraca written in the oldest examples known of Hebrew script. They were found in a burnt layer (level II) immediately beneath the mid-fifth century Persian layer and thus seem to have been written very shortly before the Babylonian sack of Jerusalem in 586 BCE, perhaps ranging up to three or four years before that event. 
- Your servant Hoshayahu has sent (this letter) to report to my lord Yaush: May the LORD let my lord hear a report of well being and a report of goodness. And now, please open the eyers) of your servant as to (the purpose of) the letter that he sent to your servant last night, for the heart of your servant has been sick since you . sent (it) to your servant. For my lord said: "You don't know how to read it!" As The LORD lives, nobody has ever attempted to read for me a letter! And moreover, every letter that comes to me, when I have read it, afterwards I can repeat it (in) detail! Now your servant has received (a report) saying (that) the military general Koniyahu son of 'El-Natan has gone down to enter Egypt. Concerning Hodavyahu son of'Ahiyahu and his men, he has sent (word) to take them from here. And (as for) the letter of Tobiyahu, servant of the king (that) came to Shallum son of Yada' from the prophet saying "Beware," your servant is sending it to my lord. (Ostracon 3)
- May The LORD allow my lord to witness a good harvest today. Is Tobiyahu going to send royal grain to your servant? (Ostracon 5)
The letters appear to be the communications between a military commander Yaush and someone of lower rank called Hoshayahu. They testify to literacy well beyond the royal court or scribal school, and the ostraca mention prominently a keeper of royal grain called Tobiyahu. B. Mazar traces the genealogy of the Tobiads to the Tobiyahu of the Lachish ostraca, though not all scholars agree. The ostraca combined with the Zenon papyri and Josephus making a strong case for Mazar's proposition of a Tobiad dynasty of trans-Jordanian tax-collectors.
It is difficult to reconstruct a single historical context for the letters based on such a limited sample. But it is apparent that the Babylonian invasion of Judah had not yet begun since one could travel in some safety from Lachish to Jerusalem, and harvesting crops in the Lachish's environs was still possible. It is in this context that another letter informs us of an Israelite military commander who was sent to Egypt, probably to obtain military support from Pharaoh Apries (589-570 BCE) in the imminent war against Babylon.
One distinctive feature found in the ostraca, but not found in Jehoshaphat's Tobiyah is the title "Tobiah servant (or slave) of the king" in ostracon III:19. It is possible that the term servant/slave simply means a royal official. However, several generations later Nehemiah would use the term "Tobiah, the Ammonite slave."
Ammon or Ammonites (Hebrew: עַמּוֹן), also referred to in the Bible as the "children of Ammon," were a people (also known from Assyrian and other records) living east of the Jordan river whose origin biblical tradition traces to an illegitimate son of Lot, the nephew of the patriarch Abraham, as with the Moabites. The Ammonites were regarded by Jewish tradition as close relatives of the Israelites and Edomites. Attacks by the Ammonites on Israelite communities east of the Jordan were the impetus behind the unification of the tribes under Saul, who defeated them.
In 2 Samuel 12:31, King David is described enslaving the Ammonites: "put them under saws, and under harrows of iron, and under axes of iron, and made them pass through the brick-kiln: and thus did he unto all the cities of the children of Ammon". David's treatment of the captives is generally interpreted to mean that he employed them as laborers in various public works. At this time the Ammonites and other neighboring peoples in the trans-Jordan, received the definition of "slave" according to Jewish law. The class system of "slave" would persist through the matrilineal line, even if the sovereign no longer exorcised authority over them.
In the time of Nebuchadnezzar, the Ammonites seem to have been fickle in their political attitude. They assisted the Babylonian army against the Jews; encroached upon the territory of the Gad; and occupied Heshbon and Jazer; but the prophetic threatenings in Jeremiah 9:26, 25:21, 27:3, and Ezra, 21:20, point to rebellion by them against Babylonian supremacy. They received Jews fleeing before the Babylonians (Jeremiah 40:11), and their king, Baalis, instigated the murder of Gedaliah, the Babylonians' Jewish governor of Jerusalem and its environs by the Edomite-Judahite prince Ishmael.
It is possible that the Tobiad governors of Ammon, after intermarrying with the Ammonite royal family inherited the epitath "the Ammonite slave". Since this servitude derives from the conquest of royalty, and his affairs were not regulated day to day by his "master", the trans-Jordanian "slave" would have several advantages. He would be considered a Jew and partake of the Temple sacrifices. But he would only be bound by the laws "which are not time-bound", releasing him from the performance of most ritual. In this way the Tobiad tax-collectors, through their marriage alignments with the Ammonite royal family, would become "slaves" to the king, fully Jews but released from most ritual, free to pursue prophetic or philosophical interests according to their tastes. The Tobiads appear to have done both.
- Persia & Creation of Judaism, Book 6., Dating Ancient Near Eastern History (Part II), by Peter James; CAIS The Circle of Ancient Iranian Studies, 1998
- Mazar 1957, 229-238
- Some scholars, identifying the Tobiad in the Lachish ostraca as the identical to that of Ezra-Nehemiah, date the ostraca to the post-exilic period. Cf. Persia & Creation of Judaism, Book 6., Dating Ancient Near Eastern History (Part II), by Peter James; CAIS The Circle of Ancient Iranian Studies, 1998
- Often assumed to be Jeremiah, however on circumstantial and uncertain grounds. “The Prophet” in the Lachish Ostraca D. Winton Thomas, M.A. Regius Professor of Hebrew and Fellow of St. Catharine’s College, Cambridge.; The Tyndale Old Testament Lecture, 1945
- "The Lachish Ostraca." by Prof. Scott B. Noegel Chair, Dept. of Near Eastern Languages and Civilization University of Washington; First Published in: Mark W Chavalas, ed. The Ancient Near East: Historical Sources in Translation London: Blackwell (2006), 400-403.
- Mazar 1957, 229-238
- Eskenazi 1992, 585.
- If B. Mazar's reconstruction is correct, the name Tobiah alternates over at least nine generations of Tobiads. This is supported by newly published Ammonite inscriptions.
- Nehemiah 4:1