Overall meaning : Allah commands His Prophet, Muhammed, may Allah bless him and grant him peace, to warn with the Qur’an those who truly benefit from it—those who fear being gathered before their Lord on the Day of Judgement, when there will be neither a protector nor an intercessor for them besides Him, for on that day, they will have no protector or intercessor who can intercede for them before Allah and save them from His punishment if He decides to punish them—so that they may fear Him by doing what He commands and avoiding what He forbids.
Allah then enjoins him not to send away those who sincerely call upon Him, Glorified and Exalted be He, morning and evening, thereby seeking His good pleasure, and informs him that each one will be accountable only for himself: He is by no means accountable for what they do just as they are by no means accountable for his actions. Therefore, he should not drive them away; otherwise, he will be of the wrongdoers who transgress His limits.
Just as Allah tries these rich unbelievers by means of these poor believers, He asserts, so too He tries people by making some of them rich and some of them poor, some of them high-born and some others low-born. When the poor and the weak embrace the faith, this becomes a trial for the rich and noble, with the result that the latter disdainfully say of the believers who are poor and lacking in recognized social status, 'Are these the ones Allah has favoured among us by guiding them to Islam? By no means! Had there been any good in it, we would have been worthier of embracing it.’ To this, Allah replies, saying that He knows full well those who give thanks to Him, and so He assists and guides them because of their gratefulness.
Then He directs His Prophet, Muhammad, may Allah bless him and grant him peace, to heartily welcome those who believe Allah’s revelations and signs when they come to him and honour them by saying to them, 'Peace be upon you’, give them the good news of Allah’s all-embracing mercy which He has made incumbent on Himself and to inform them that if anyone among them commits a sin in ignorance and then afterwards repents and mends his ways, Allah will not punish him for it, for He is All-Forgiving, All-Merciful.
He also informs him that just as He has previously explained His arguments against the Arab idolaters and unbelievers and distinguished truth from falsehood, so too He clearly spells out His proofs by establishing truth and refuting falsehood so that the path of unbelievers leading to His wrath and punishment will be made clear and thus be avoided, and in order to distinguish truth from falsehood.