مَّا يُقَالُ لَكَ إِلَّا مَا قَدْ قِيلَ لِلرُّسُلِ مِن قَبْلِكَ ۚ إِنَّ رَبَّكَ لَذُو مَغْفِرَةٍ وَذُو عِقَابٍ أَلِيمٍ Qur’an Fussilat (41:43)Ma yuqalu laka illa ma qad qeela lilrrusuli min qablika inna rabbaka lathoo maghfiratin wathoo AAiqabin aleemin
This is an allusion to the allegation of the Prophet's opponents that he himself was the "author" of what he claimed to be a divine revelation, as well as to their demand that he should "prove" the truth of his prophetic mission by producing a miracle: a scornful attitude with which all the earlier prophets had been confronted at one time or another, and which is epitomized in the "saying" of the unbelievers mentioned in verse {5} of this surah.
The gist of Allah's Message, now, before, and for ever, is the same: Mercy to the erring and repentant; just punishment to those who wilfully rebel against Allah.