Allah said to His Prophet, when the disbelievers asked him to hasten on the punishment for them:

meaning, 'Allah has sent me to you to warn you ahead of the terrible punishment, but I have nothing to do with your reckoning. Your case rests with Allah: if He wills, He will hasten on the punishment for you; and if He wills, He will delay it for you. If He wills he will accept the repentance of those who repent to Him; and if He wills, He will send astray those who are decreed to be doomed. He is the One Who does whatsoever He wills and wants and chooses.

{There is none to put back His judgement and He is swift at reckoning.} [13:41]

means, whose hearts believe and whose actions confirm their faith.

means, forgiveness for their previous bad deeds, and a great reward in return for a few good deeds. Muhammad bin Ka'b Al-Qurazi said, "When you hear Allah's saying:

{Rizq Karim} this means Paradise."

Mujahid said, "To discourage people from following the Prophet." This was also the view of 'Abdullah bin Az-Zubayr, "to discourage." Ibn 'Abbas said, "To frustrate them means to resist the believers stubbornly."

This refers to the agonizingly hot Fire with its severe punishment, may Allah save us from it. Allah says:

{Those who disbelieved and hinder (men) from the path of Allah, for them We will add torment to the torment because they used to spread corruption} [16:88]