  In the preface to the translation of the Guide, Ibn Tibbon explains that, when confronted with difficult terms, he would consult Arabic dictionaries. He does not say which dictionaries he consulted, but a report by Todros Todrosi, in the preface to his fourteenth-century translation of Averroes’ Middle Commentary on Aristotle’s Rhetoric (ed. J. Goldenthal, Leipzig, 1842, p. 3), provides an exact reference: al-Khalil b. Ahmad’s Kitab al-‘ayn. Todrosi’s report reads as follows: