However, it's important to note that this phrase is rarely used alone. It often appears in contexts where it's a part of a longer phrase, such as:
* "La source devant l'église" - "The source in front of the church".
* "Placer la source devant la caméra" - "Place the source in front of the camera".
Therefore, the exact meaning of "source devant" in English would depend on the context.
To understand the specific meaning, you need to consider the full sentence and the situation it describes.