Surat Hud (11-12)

{إِلاَّ الَّذِينَ صَبَرُواْ وَعَمِلُواْ الصَّالِحَاتِ أُوْلَـئِكَ لَهُم مَّغْفِرَةٌ وَأَجْرٌ كَبِيرٌ} [هود : 11]

11- As for patient believers who have done righteous actions after believing in Allah and devoted themselves to Him, when an adversity hits them, they show patience until Allah brings ease. Moreover, when Allah bestows goodness and good health, they show gratitude and do not forget the rights of people; those are the people whom Allah forgives their sins and rewards them for their good actions as a retribution of their patience for adversities and gratitude for favors.

{فَلَعَلَّكَ تَارِكٌ بَعْضَ مَا يُوحَى إِلَيْكَ وَضَآئِقٌ بِهِ صَدْرُكَ أَن يَقُولُواْ لَوْلاَ أُنزِلَ عَلَيْهِ كَنزٌ أَوْ جَاء مَعَهُ مَلَكٌ إِنَّمَا أَنتَ نَذِيرٌ وَاللّهُ عَلَى كُلِّ شَيْءٍ وَكِيلٌ} [هود : 12]

12- O Prophet, perhaps you leave some of Allah's Revelations to you and your chest becomes tight by the words of the disbelievers which reflect their bad attitudes.

The disbelievers used to mock at the Qur'an, consequently the Prophet (peace be upon him)'s chest got tight and refused to make them hear what they disapprove and mock at, so the Ayah strengthened his determination not to do so.

The disbelievers said: Would abundant money be given to this Messenger or an angel comes to certify him?

So, do not make your chest tight by their words or their suggestions which they use to mock at you, for you are not a guardian over them or over their faith. You are only an informer and Allah is the one who runs everything and the keeper to everything, who knows those who deserve guidance and those who deserve falsehood.