3 My chief reason, however, for suspecting the genuineness of this verse is what I said before, that in all my search of the writings of Moses I have found no prophecy of Christ. But now that I have found in you a reader of superior intelligence, I hope to learn something; and I promise to be grateful if no feeling of ill-will prevents you from giving me the benefit of your higher attainments, as your lofty style of reproof entitles me to expect from you. I ask for instruction in whatever the writings of Moses contain about our God and Lord which has escaped me in reading. I beseech you not to use the ignorant argument that Christ affirms Moses to have written of Him. For suppose you had not to deal with me, as in my case there is an obligation to believe Him whom I profess to follow, but with a Jew or a Gentile, in reply to the statement that Moses wrote of Christ, they will ask for proofs. What shall we say to them? We cannot quote Christ's authority, for they do not believe in Him. We must point out what Moses wrote.
Source: Reply to Faustus the Manichaean (New Advent)