Sirach 6:33
Ben Sira, Ecclesiasticus31 You will wear her like a glorious robe, and put her on like a splendid crown. 32 If you are willing, my child, you can be disciplined, and if you apply yourself you will become clever. 33 If you love to listen you will gain knowledge, and if you pay attention you will become wise. 34 Stand in the company of the elders. Who is wise? Attach yourself to such a one. 35 Be ready to listen to every godly discourse, and let no wise proverbs escape you.
Clement of Alexandria Stromata 2.5
For it were strange that the followers of the Samian Pythagoras, rejecting demonstrations of subjects of question, should regard the bare ipse dixit as ground of belief; and that this expression alone sufficed for the confirmation of what they heard, while those devoted to the contemplation of the truth, presuming to disbelieve the trustworthy Teacher, God the only Saviour, should demand of Him tests of His utterances. But He says, "He that hath ears to hear, let him hear." And who is he? Let Epicharmus say: "Mind sees, mind hears; all besides is deaf and blind." Rating some as unbelievers, Heraclitus says, "Not knowing how to hear or to speak;" aided doubtless by Solomon, who says, "If thou lovest to hear, thou shalt comprehend; and if thou incline thine ear, thou shalt be wise.
Notes and References
"... The Hebrew of Ben Sira was not included in the Jewish biblical canon. Testimony to its survival, however, is found in the numerous quotations of the book in rabbinic literature. Of course, the medieval manuscripts discovered in the Cairo Genizah constitute prima facie evidence for its continued existence in Hebrew. The Greek translation seems to have been in uential in early Christianity, and it eventually was included in the Christian Old Testament (only to be excised by Protestants in the sixteenth century). Sirach is not cited explicitly in the New Testament, and scholars differ as to how much in uence it had on the New Testament writings. Those who see broad influence have argued for it primarily in Matthew, Luke, some of Paul’s letters and the Epistle of James (compare Harrington, Invitation, p. 90; Schürer, History, vol. III.1, pp. 205–208). In other early Christian literature, Didache 4:5 and Barnabas 19:9 bear a very close resemblance to, and perhaps are taken from, Sirach 4:31. If these texts do depend on Sirach, they would be the earliest examples of direct Christian use of the book. A healthy number of Greek and Latin church fathers, including Clement of Alexandria, Origen, John Chrysostom, Tertullian, Jerome and Augustine, use Sirach in their writings, and as early as Clement of Alexandria Sirach is cited as scripture, demonstrating the high regard the book came to have in Christian tradition ..."
Ryan, Daniel "Sirach (Ecclesiasticus)" in Aitken, J. K. (ed.) T&T Clark Companion to the Septuagint (pp. 410-424) T&T Clark International, 2015