Well pretty much the title says it all, I am Bulgarian native speaker and we have way of saying this which literally translated is "clean coin".
For instance: "I am taking his words as a clean coin." (but this is really translated literally so I expect to mean gibberish in English)
Context in which I would like to use this idiom:
"We've been working together for quite some time now and I never saw him make a mistake, henceforth I am taking his bug reports ______."
What I mean is that this guy I am referring to has not made any false bug reports or in other words bug reports that later turned out to be invalid or not real bugs.
Also when I refer to the word bug I am using it in the context of software development.
Best Answer
We don't say it quite like Bulgarian. Instead in English we "take his word for it", as in: "I am taking his word for it". The idiom can be expanded to include "at face value", as in "to take his word at face value".
For example: I said to my friend, "The American told me that in the United States you should tip the waiter after paying the bill." My friend replied, "But we don't usually tip in Bulgaria; why should I tip in the United States?" I replied, "I don't know, but I am taking his word for it."
In the above situation, the first person is inclined to believe the American and has taken his statement (words) "at face value", even though the friend "has his doubts". Cascabel refers to "...Good as Gold" which is a contraction of the saying: "his word is as good as gold", which implies expertise in the field.