"In about 800 C.E. some Heberw manuscripts were discovered near Jericho. According to a letter written by Timotheus I (726-819 C.E.), the Nestorian partriarch of Seleucia, to the archbishop of Elam, an Arab hunter's dog had pursued an animal into a cave near the Dead Sea. When the hunter went to look for his dog, he found "a cave in the rock and many books therein." The hunter then took his loot to Jeruslaem, where at least some of the manuscripts were identified as books of the Bible written in Hebrew. In all probability, these manuscripts came from the same set of caves in which the Dead Sea Scrolls were found under similar circumstances in 1947 and during the decade thereafter."
James A. Sanders and Astrid Beck, "The Leningrad Codex: Rediscovering the Oldest Complete Hebrew Bible," Bible Review August (1997): 32-41,46, s. 36-37.