Tafsir of Al-Waqi'ah 56:47

{And they used to say, "When we have died and become dust and bones..."} (up to the end). If it is said: "This necessitates repetition," then the answer is that what is intended by the first mention is to describe them as being steadfast upon their false oath, and consequently, to describe them as persistent in their denial, while pointing to an argument of manifest corruption; although there is no prohibition in repeating that which indicates denial, for it serves as a preamble and a foundation for explaining its falsity.

The meaning of their statement "we have become dust and bones" is that some of our parts—such as flesh, skin, and the like—had become dust, and some of them had become decayed bones. The mention of dust is placed first because it is further removed from the state of life, which is what their denial of resurrection demands.

The word "when" (idha) is purely for setting a temporal context, and the operative word governing it is what the Almighty’s saying, "Are we indeed to be resurrected?" indicates. It is the verb "to be resurrected" itself, for there are multiple reasons that prevent what follows it from operating on what precedes it. This is the object of the denial, and its restriction to the aforementioned time is not for the purpose of limiting their denial to that moment alone; for they were deniers of life after death even if the body remained intact. Rather, it is to strengthen the denial of the resurrection by directing it toward a state that is completely incompatible with it. This is akin to an argument for what they claim. The repetition of the hamza [in a-idha] is to emphasize the act of denial, and the beginning of the sentence with inna is for the purpose of emphasizing the denial, not denying the emphasis.