Accounts of error-correcting codes always start with the (3,1)-repetition code — transmit three copies of each bit, and let them vote, choosing the best two out of three when there is disagreement. Apparently this code has been in use for longer than anyone had realised, to judge by this passage from the Jerusalem Talmud:
Three scrolls [of the Torah] did they find in the Temple courtyard. In one of these scrolls they found it written “The eternal God is your dwelling place (maon)“. And in two of the scrolls it was written, “The eternal God is your dwelling place (meonah)”. They confirmed the reading found in the two and abrogated the other.
In one of them they found written “They sent the little ones of the people of Israel”. And in the two it was written, “They sent young men…”. They confirmed the two and abrogated the other.
In one of them they found written “he” [written in the feminine spelling] nine times, and in two they found it written that way eleven times. They confirmed the reading found in the two and abrogated the other. (tractate Ta’anit 4:2, trans. Jacob Neusner)
(h/t Masorti Rabbi Jeremy Gordon, who alluded to this passage in an inter-demominational panel discussion yesterday at the OCHJS. He was making a different point, which for some reason had very little to do with information theory.)