Mishnah 3 - Chapter 6 - Pirkei Avot

Halomed mechavero perek echad o halachah echat o pasuk echad o dibbur echad o afilu ot echat, tzarich linhag bo kavod, shekken matzinu bedavid melech yisra'el, shello lamad me'achitofel ella shenei devarim bilvad, kera'o rabbo allufo umeyudda'o, shenne'emar ve'attah enosh ke'erki allufi umeyudda'i, vahalo devarim kal vachomer, umah david melech yisra'el shello lamad me'achitofel ella shenei devarim bilvad kera'o rabbo allufo umeyudda'o, hallomed mechavero perek echad o halachah echat o pasuk echad o dibbur echad o afilu ot echat al achat kammah vechammah shetzarich linhag bo kavod, ve'ein kavod ella torah, shenne'emar kavod chachamim yinchalu utemimim yinchalu tov, ve'ein tov ella torah shenne'emar ki lekach tov natatti lachem torati al ta'azovu.

One who learns from his fellow one chapter, or one halakhah, or one verse, or one word, or even one letter, is obligated to treat him with honor; for so we find with David, king of Israel, who learned from Ahitophel no more than two things, yet called him his master, his guide and his beloved friend, as it is said, “But it was you, a man mine equal, my guide and my beloved friend” (Psalms 55:14). Is this not [an instance of the argument] “from the less to the greater” (kal vehomer)? If David, king of Israel who learned from Ahitophel no more than two things, nevertheless called him his master, his guide and his beloved friend; then in the case of one who learns from his fellow one chapter, or one halakhah, or one verse, or one word, or even one letter, all the more so he is under obligation to treat him with honor. And “honor’” means nothing but Torah, as it is said, “It is honor that sages inherit” (Proverbs 3:35). “And the perfect shall inherit good” (Proverbs 28:10), and “good” means nothing but Torah, as it is said, “For I give you good instruction; do not forsake my Torah” (Proverbs 4:2).

If one learns from his friend one chapter or one halachah or one verse or one word or even one letter, he must accord him honor. For thus do we find with David, king of Israel, who learned from Achitofel two things alone and called him his master, his teacher, and his preceptor, as it is written (Psalms 55:14): "And you (Achitofel), a man of my regard, my teacher and my preceptor." Now does this not follow a fortiori, viz.: If David, king of Israel, who learned from Achitofel only two things alone, called him his master, his teacher and his preceptor — then one who learns from his friend one chapter or one halachah or one verse or even one letter, how much more so should he accord him honor! And there is no honor but Torah, as it is written (Proverbs 3:35): "The wise inherit honor," and (Ibid 28:10): "And the perfect (in Torah) will inherit good," and there is no "good" but Torah, viz. (Ibid. 4:2): "For a goodly acquisition have I given you — do not forsake My Torah."