These Ayahs refer to the fact that Divine signs followed, if necessary, by Divine wrath are a warning for the deviated people to return to the path of monotheism and virtue.
وَمَا نُرِيهِم مِّنْ آيَةٍ إِلَّا هِيَ أَكْبَرُ مِنْ أُخْتِهَا وَأَخَذْنَاهُم بِالْعَذَابِ لَعَلَّهُمْ يَرْجِعُونَ وَقَالُوا يَا أَيُّهَ السَّاحِرُ ادْعُ لَنَا رَبَّكَ بِمَا عَهِدَ عِندَكَ إِنَّنَا لَمُهْتَدُونَ فَلَمَّا كَشَفْنَا عَنْهُمُ الْعَذَابَ إِذَا هُمْ يَنكُثُونَ
“And We did not show them a sign but it was greater than the other, and We seized them with punishment so that they might return (to monotheism). They would say, ‘O magician! Invoke your Lord for us by the covenant He has made with you; we will indeed be guided.’ But when We lifted the punishment from them, behold, they would break their pledge.”
When the Pharaoh and his people denied the truth and became proud of their wayward and sinful behaviour, God Almighty commanded Moses to demonstrate to them a greater miracle than the previous one, including the inflicting of torments upon the disbelievers, such as swarms of locusts that destroyed their crops.
Following this, the terrified disbelievers pleaded to Moses that they would believe provided that the affliction was removed. As indicated by Ayah 49 it seems the common people were too ignorant to draw a distinction between miracle and sorcery. They regarded Moses as a great sorcerer and beseeched him to invoke his Lord to remove the torments, but as Ayah 50 says, after the removal of the affliction, they broke their promise and persisted in their disbelief.
These Ayahs teach us that:
1. We should take lessons from the account of Prophet Moses, the tyrannical Pharaoh and the ever ungrateful Israelites, who always conspired against truth and disobeyed the Words of God.
2. These Ayahs also serve as a warning to the obdurate enemies of Islam to reflect on the fate of the disbelievers of the past and take lessons from their dire fate.
3. Many people at the time of danger become heedful of God and start praying but when the calamity is gone, they again become negligent of Divine Power and the obligations of religion.
4. Once God the All-Merciful articulates His argument through revelation of Divine signs and gives ultimatum to the non-believers, the only way left would be punishment and worldly torture so that people would return to the path of truth lest punishment in Hell become thier fate.