Shaykh Muḥammad Ṣāliḥ al-‘Uthaymīn
As for translation, it is transmitting the meaning of a speech from a language to another language. Transmitting speech from a language to another language.
And there are two or three conditions (needed to be met) regarding it.
The first: The translator (should have) knowledge of both languages. He should know the meaning (of the speech) in both languages – the one he is translating from and the one he is translating to.
The second: He (should have) knowledge about the subject matter, because knowing the subject matter is very important in translating. He who does not have knowledge about the subject matter might translate a statement to other than it’s intended (meaning).
Hence, it is a must for him to have knowledge about the subject matter, and this is different from knowing the meaning (of the speech).
The third condition is that he should be trustworthy. And here, trustworthiness (as a condition) is taken from the author’s statement: “[E]xcept the statement of two trustworthy persons.”
So, if he is not trustworthy, then his translation is not accepted.