Theonas of Alexandria (bishop 282-300):
"Let no day pass by without reading some portion of the Sacred Scriptures, at such convenient hour as offers, and giving some space to meditation. And never cast off the habit of reading in the Holy Scriptures; for nothing feeds the soul and enriches the mind so well as those sacred studies do."
Source: ANF: Vol. VI, The Epistle of Theonas, Bishop of Alexandria, To Lucianus, §9.
For an excellent compilation of quotes of the Church fathers teaching on the primacy, sufficiency and ultimate authority of Scripture, get a copy of Holy Scripture:The Ground and Pillar of Our Faith Vol III- The Writings of the Church Fathers Affirming the Reformation Principle of Sola Scriptura.