Who are the people for whom no weight be assigned on the Day of Judgement?

Verses 103-106 of Chapter 18:

Say: "Shall We tell you the greatest losers in respect of (their) deeds''. "Those whose efforts have been wasted in this life while they thought that they were acquiring good by their deeds.'' "They are those who deny the Ayat of their Lord and the meeting with Him. So their works are in vain, and on the Day of Resurrection, We shall assign no weight for them.'' "That shall be their recompense, Hell; because they disbelieved and took My Ayat and My Messengers for jest.''