15. "Has the story of Moses reached you?"
16. "When his Lord called to him in the holy valley of Tuwa:"
17. "Go to Pharaoh, surely he has transgressed all bounds:"
18. "And say to him: 'Wouldst thou that thou shouldst be purified (from
sin) ?' "
19. 'And that I guide thee to thy Lord, so thou shouldst fear (Him)?'
20. "Then did (Moses) show him The Great Sign."
21. "But (Pharaoh) rejected it and disobeyed (guidance);"
22. "Further, he turned his back striving hard (against Allah)."
23. "Then he collected (his men) and made a proclamation,"
24. "And said: I am your Lord, Most High."
25. "So Allah seized him for an exemplary punishment in the Hereafter
and in this life.
26. "Surely in that is a lesson for him who fears (Allah).
Pharaoh used to say: I am your Lord, Most High.
After a considerable description in the former verses about Resurrection and the rejection of the unbelievers, in the following verses the painful end of Pharaoh, one of the great arrogant blasphemers and rebels of history, is pointed out, to show Pagan Arabs that those who were stronger than them could not stand against Allah's wrath and punishment, and encourages the believers not to be afraid of the apparent strength of their enemies, because it is easy for Him to destroy them all.
"Has the story of Moses reached you?"
It is interesting that it addresses the Prophet (p.b.u.h.) and begins with a question to attract the attention of the listener in order to make him ready to hear this wonderful story.
"When his Lord called to him in the holy valley of Tuwa."
'Tuwa' may be the name of a sacred valley just below Mount Sinai, which was located in Sham (Damascus) between Madyan and Egypt, and where Moses, subsequently, received, in his heart, the first light of inspiration. The term is also mentioned in Sura Ta-Ha, No. 20, verse 12 where Moses hears a voice say: "Verily I am thy Lord! therefore (in My presence) put off thy shoes: thou art in the sacred valley Tuwa."
Or, it has a descriptive meaning derived from the term /tay/ which means 'the act of rolling up', as if the land is rolled up in holiness and sanctity, or as Raqib cites: Moses should cover a long distance to be prepared to receive the inspiration, but Allah rolled up the way and made it near for Moses to reach the goal.
Then, in three short, but meaningful sentences, it refers to the message that Allah sent to Moses in that valley where He commanded:
"Go to Pharaoh, surely he has transgressed all bounds.
"And say to him: 'Wouldst thou that thou shouldst be purified (from sin?'
"And that I guide thee to thy Lord, so thou shouldst fear (Him)?"
And, since invitations should be accompanied by reasons, in the next verse it says: "Then did (Moses) show him The Great Sign."
The Great Sign, whether being the 'white shining hand' or the rod that became a 'snake active in motion' or both of them, has been one of the Great Signs that Moses relied on in the prime of his prophetic mission.
There are some interesting points in these four verses that should be noted:
1. It says that Moses is told to go to Pharaoh, because he has transgressed, and this shows that one of the great missions that the prophets had was to guide the rebels or to oppose them decisively.
2. This invitation to purity, by Moses, with those conciliatory words and in the most benevolent terms, to Pharaoh, where Allah tells Moses to go: "And say (to him) 'Wouldst thou that thou shouldst be purified (from sin)?'" is similar to the sense found in Sura Ta-Ha, No. 20, verse 44 which says: "But speak to him mildly ...".
3. This meaning has a delicate hint to the fact that the goal of the prophecy of the prophets is to purify men and lead them to their real purified nature. By the way, it does not say 'I purify you', it says: "...Wouldst thou that thou shouldst be purified ?...", which indicates that purification should come about from inside and by one's own intention; not from an imposition from an outside source.
4. The statement of 'guidance' after mentioning the sense 'to purify' is a reason for showing that 'purification' is a preliminary step to 'guidance'.
5. The term /rabbika/ 'your Lord', indeed, is an emphasis on this fact that 'I take you to Him Who is your master and your cherisher. Why do you flee from the path of happiness? '.
6. 'Fear of Allah' is the fruit of guidance. Truly, those who are guided to monotheism feel responsible before Allah, the Almighty, because fear of Allah never appears without knowing Him. That is why in Sura Fatir, No, 35, verse 28 it says: "...those truly fear Allah among His Servants, who have knowledge...".
7. First, Moses appeals to Pharaoh's emotional guidance and then, he evokes his rational and logical guidance by showing him his Great Sign, his great miracle. The most effective way of preaching is by influencing emotions and, then, presenting the reasons and evidences.
Now, we will deal with Pharaoh and his reaction to so much affection and love and the beautiful, reasonable speech and the Great Sign that Moses showed him.
The fact is that many signs were given, but Pharaoh and his men were steeped in arrogance.
"But (Pharaoh) rejected it and disobeyed (guidance)".
This shows that rejection is the primary step in transgression, as well as faith, and admitting the truth is paramount to obedience.
Pharaoh was not satisfied with only rejecting the guidance.
"Further, he turned his back, striving hard (against Allah)".
Since the miracle of Moses threatened the whole devilish unity of Pharaoh, he sent some men to different cities to gather the sorcerers and he also ordered to announce people to come to see the challenge between the sorcerers and Moses.
"Then he collected (his men) and made a proclamation".
Though the term /haŝara/ is mentioned, here, alone, but with reference to the term /haŝirin/ in Sura Araf, No. 7, verses 111-112 which say: "...and send to the cities men to collect", "And bring up to thee all (our) sorcerers well-versed", and also referring to the term /nada/ 'made a proclamation', though it is absolute, it points to the invitation of Pharaoh to the people to gather and watch the challenge; with the evidence from Sura Shuara, No. 26, verse 39 which says: "And the people were told: Are you (now) assembled?"
He did not quit with these plots and he made claims with the worst statements.
"And said: I am your Lord, Most High."
Verily, it is amazing that these arrogant transgressors, when riding on the horse-back of pride, know no limit for their selfishness. They are not content with their claim of being Lord; they want to be 'Lord of Lords'.
This statement denotes that he says, "If you worship idols, it is accepted, but I am the highest of all and I am your Lord."
And, it is interesting that Pharaoh, himself, was one of the idol-worshippers as Sura Araf, No. 7. verse 127 attests to: " ...wilt thou leave Moses and his people, to spread mischief in the land, and so to abandon thee and thy gods?", but here, he claims that he is their Lord, Most High, that is, he considered himself still higher than his own god; and this is in the vain statements of all transgressors.
And, more astonishing than this is that in Sura Qasas, No. 28, verse 38 he claims "...No god do I know for you but myself..." ; but in the current verse he goes further and says: "I am your Lord, Most High" and this is the manner of these air-headed rebels.
He reached the ultimate point of disobedience and deserved the most painful punishments. He and his corrupted surroundings should perish by the order of Allah, that is why, in the next verse, it says:
"So Allah seized him with an exemplary punishment in the Hereafter
and in this life".
The term /nakal/ originally means 'weakness' and 'disability', so it is said of a person who fails to pay his debt and since the divine chastisement makes people weak and stops others from doing sin; it is called /nakal/.
The term /nakal-al-axirah/ means 'the chastisement of the Hereafter' which will envelop Pharaoh and his people and because of its importance it is mentioned first and the term /ula/ 'former life' which meant 'the punishment in this world', is mentioned second and is that which destroyed Pharaoh and all his followers in waters of the sea.
There is another commentary which says that /ula/ means 'the first word that Pharaoh said claiming to be a deity' (Sura Qasas, No. 28, verse 32), and /axirah/ refers to the last word that he said in which he claimed that he was their Lord, Most High. Then, Allah punished him for these two blasphemous statements, even in this life.
This very idea is narrated in a tradition from Imam Baqir who added that 40 years had elapsed between the occurrence of these two statements (meaning that Allah did not just punish him to complete the argument). 
This commentary is more fitting with the term /axaDa/ which is a verb in the past tense, and indicates that the punishment was completely fulfilled in the present world, and also with the next verse that considers the event to be a lesson.
"Surely in that is a lesson for him who fears (Allah)".
This verse clearly shows that learning a lesson from these events is possible only for those who, more or less, fear Allah and possess a feeling of responsibility in their hearts.
Yes, that was the destiny of Pharaoh, the blasphemer; an example to make other pagans and chiefs of the Arab unbelievers and all those who follow on the path of Pharaoh, in any age, understand the facts and know that Allah's law is always true, firm and unchangeable.
A Small Sample of the Elegance of Holy Qur'an.
Careful attention paid to the above eleven short verses is enough to show us the fine elegance and fluency of Qur'an; a summary of the statements and activities concerning Moses and Pharaoh the motive of prophet hood, its aim, the means of purification, the manner of invitation, kinds of actions and reactions, the description of Pharaoh's plot, some examples of his vain claims, and, finally, the painful punishment of this arrogant blasphemer, which can, consequently, teach a lesson to all those who have insight, are illustrated.
 Majma-al-Bayan, vol. 10, p.