These verses have been explained earlier but we will look at them from another angle. According to the first verse the opponents of the Last Messenger were standing up against him and said in mockery: “Shall we direct you to a man who will tell you (that) you will be created anew after you have fully disintegrated into the earth fully.” They used to propagate it as a sign of madness and if he is sane they said then “Has he invented a lie or is he stricken with madness?”
In the second verse the people of Thamud speak about their apostle Saleh. The meaning of the verse is the same for they were surprised about what the apostle Saleh said and regarded his words as lies or the conjectures of an insane person.
So we learn that the Last Messenger, the apostle Saleh and other prophets spoke about the physical resurrection or else the treatment they received would be meaningless. This is just another set of proofs about physical resurrection.