“NO” means: “O Muhammad, do not repeat what had happened with the blind man.”
Here, Allah (swt) moves on to the most important topic:
O Muhammad, your call and the path that you walk upon, which is the Qur’an, is a reminder. It is not to be carried out except with gentleness, through convincing, evidences and proofs. You are to remind their origin which is of course the “Fitrah” which means the innate nature. As the human being has a natural propensity to believe in Allah (swt). Allah says:
﴾وَإِذْ أَخَذَ رَبُّكَ مِن بَنِي آدَمَ مِن ظُهُورِهِمْ ذُرِّيَّتَهُمْ وَأَشْهَدَهُمْ عَلَىٰ أَنفُسِهِمْ أَلَسْتُ بِرَبِّكُمْ ۖ قَالُوا بَلَىٰ ۛ شَهِدْنَا ۛ أَن تَقُولُوا يَوْمَ الْقِيَامَةِ إِنَّا كُنَّا عَنْ هَٰذَا غَافِلِينَ﴿
(And (remember) when your Lord brought forth from the Children of Adam, from their loins, their seed (or from Adam’s loin his offspring) and made them testify as to themselves (saying): “Am I not your Lord?” They said: “Yes! We testify,” lest you should say on the Day of Resurrection: “Verily, we have been unaware of this.” )
(Al-A’raaf : 172)
Therefore, when there is complacence or a change in environment, it is the role of the Prophets to carry out purification.