What does the word "repay" in essence mean in the phrase "the book repays close study"?
My OED defines "repay" as
to make return for; requite [a service, action, etc.]... must repay their kindness
Which is clear as a bell to me. However, the context that doesn't seem to go home is what it means to "requite" or "make return for" close study.
The Oxford's definitions for close and study that seem plausible to me are these:
1. concentrated, searching, e.g. "close examination"; "close attention".
2. Leaving no gaps or weaknesses, rigorous [strict, severe], e.g. "close reasoning".
1. the devotion of time and attention to acquiring information or knowledge, esp. from books.
2. the portrayal in literature or another art form of an aspect of behaviour or character etc.
To my mind, sense # 1 seems to win out and should fit for both words.
Yet, what does it mean to say that something "requites" or "pays back" thorough devotion/dedication/examination/research/inspection?
Does it by any means mean studying the book in question yields good results... pays off?