V. 5- “Now if there is anything that seems strange, strange is their (the disbelievers) saying “What! When we become dust could we then be raised to life again?” They are the people who’ve denied their Rabb, they are the ones who have chains around their necks and they are the ones who will be the inmates of hellfire to live therein forever,”
Allah (SWT) says that it is a wonder to Muhammad (S) and the believers that people deny the Message. It is not a wonder to Allah (SWT) because Allah (SWT) has knowledge of everything. Allah (SWT) goes on to tell the Prophet (S) that if you wonder about their reaction to you, a greater wonder is that they question if they will be resurrected after dying and becoming dust. Remember when the disbeliever of the Quraish came to the Prophet (S) with an old bone and crushed it to dust in front of the Prophet (S) and the other believers and said are you trying to tell us we will be brought back from this? This was a powerful statement and the Prophet (S) needed a quick response, so Allah (SWT) sent Jibreel (AS) immediately with the response, Allah (SWT) told him to tell them the One who created this bone the first time from nothing can create it again from dust.