Richard Chenevix Trench said this quote

“ ... for you will never, I trust, disconnect what you may yourselves be learning from the hope and prospect of being enabled thereby to teach others more effectually. If you do, and your studies in this way become a selfish thing, if you are content to leave them barren of all profit to others, of this you may be sure, that in the end they will prove not less barren of profit to yourselves. In one noble line Chaucer has characterized the true scholar:- And gladly would he learn and gladly teach. Resolve that in the spirit of this line you will work and live. ”