1 Timothy 4:15

Meditate--Greek, "Meditate CAREFULLY upon" (Psa 1:2; Psa 119:15; compare "Isaac," Gen 24:63). these things-- (Ti1 4:12-14). As food would not nourish without digestion, which assimilates the food to the substance of the body, so spiritual food, in order to benefit us, needs to be appropriated by prayerful meditation. give thyself wholly to--literally, "BE in these things"; let them engross thee wholly; be wholly absorbed in them. Entire self-dedication, as in other pursuits, so especially in religion, is the secret of proficiency. There are changes as to all other studies, fashionable to-day, out of fashion to-morrow; this study alone is never obsolete, and when made the all-engrossing aim sanctifies all other studies. The exercise of the ministry threatens the spirit of the ministry, unless it be sustained within. The minister must be first his own scholar before he can be another's teacher. profiting--Greek, "progress" towards perfection in the Christian life, and especially towards the fullest realization of the ideal of a Christian minister (Ti1 4:12). may appear to all--not for thy glory, but for the winning of souls (Mat 5:16).

— Jamieson-Fausset-Brown Commentary (public domain)