This is the start of Luther's preface to Romans:
"This letter is truly the most important piece in the New Testament. It is purest Gospel. It is well worth a Christian's while not only to memorize it word for word but also to occupy himself with it daily, as though it were the daily bread of the soul. It is impossible to read or to meditate on this letter too much or too well. The more one deals with it, the more precious it becomes and the better it tastes. Therefore I want to carry out my service and, with this preface, provide an introduction to the letter, insofar as God gives me the ability, so that every one can gain the fullest possible understanding of it. Up to now it has been darkened by glosses [explanatory notes and comments which accompany a text] and by many a useless comment, but it is in itself a bright light, almost bright enough to illumine the entire Scripture."
(via Trevin Wax)