In the intro of Athanasius’ De Incarnatione, C. S. Lewis compares books of devotion and books of doctrine:
Now the layman or amateur needs to be instructed as well as to be exhorted. In this age his need for knowledge is particularly pressing... For my own part I tend to find the doctrinal books often more helpful in devotion than the devotional books, and I rather suspect that the same experience may await many others. I believe that many who find that “nothing happens” when they sit down, or kneel down, to a book of devotion, would find that the heart sings unbidden while they are working their way through a tough bit of theology with a pipe in their teeth and a pencil in their hand.So Ezra set his mind to study the law of the Lord and to practice it, and to teach His statutes and ordinances in Israel [ezra 7.10].
The venerable dead are waiting in my library to entertain me and relieve me from the nonsense of surviving mortals [Samuel Davies, 1723-1761].When you come bring the cloak which I let at Troas with Carpus, and the books, especially the parchments [2 tim 4.13].
Spurgeon preached on the this text in 1863:
How rebuked are they by the apostle! He is inspired, and yet he wants books! He has been preaching at least for thirty years, and yet he wants books! He had seen the Lord, and yet he wants books! He had had a wider experience than most men, and yet he wants books! He had been caught up into the third heaven, and had heard things which it was unlawful for a men to utter, yet he wants books! He had written the major part of the New Testament, and yet he wants books!
We are quite persuaded that the very best way for you to be spending your leisure, is to be either reading or praying. You may get much instruction from books which afterwards you may use as a true weapon in your Lord and Master's service. Paul cries, "Bring the books"—join in the cry.