From: The Golden Sayings of Epictetus (translated by Hastings Crossley) - from Project Gutenberg.
First study to conceal what thou art; seek wisdom a little while unto thyself. Thus grows the fruit; first, the seed must be buried in the earth for a little space; there it must be hid and slowly grow, that it may reach maturity. But if it produce the ear before the jointed stalk, it is imperfect-a thing from the garden of Adonis. Such a sorry growth art thou; thou hast blossomed too soon: the winter cold will wither thee away!