In The Name of Allah, The Most Merciful, The Bestower of Mercy.

Allah, The Most High, said regarding the encounter between Musa, peace be upon him, and the magicians:

قَالُواْ يَـٰمُوسَىٰٓ إِمَّآ أَن تُلۡقِىَ وَإِمَّآ أَن نَّكُونَ أَوَّلَ مَنۡ أَلۡقَىٰ

 قَالَ بَلۡ أَلۡقُواْ‌ۖ فَإِذَا حِبَالُهُمۡ وَعِصِيُّهُمۡ يُخَيَّلُ إِلَيۡهِ مِن سِحۡرِهِمۡ أَنَّہَا تَسۡعَىٰ
فَأَوۡجَسَ فِى نَفۡسِهِۦ خِيفَةً۬ مُّوسَىٰ
قُلۡنَا لَا تَخَفۡ إِنَّكَ أَنتَ ٱلۡأَعۡلَىٰ
وَأَلۡقِ مَا فِى يَمِينِكَ تَلۡقَفۡ مَا صَنَعُوٓاْ‌ۖ إِنَّمَا صَنَعُواْ كَيۡدُ سَـٰحِرٍ۬‌ۖ وَلَا يُفۡلِحُ ٱلسَّاحِرُ حَيۡثُ أَتَىٰ
فَأُلۡقِىَ ٱلسَّحَرَةُ سُجَّدً۬ا قَالُوٓاْ ءَامَنَّا بِرَبِّ هَـٰرُونَ وَمُوسَىٰ
قَالَ ءَامَنتُمۡ لَهُ ۥ قَبۡلَ أَنۡ ءَاذَنَ لَكُمۡ‌ۖ إِنَّهُ ۥ لَكَبِيرُكُمُ ٱلَّذِى عَلَّمَكُمُ ٱلسِّحۡرَ‌ۖ فَلَأُقَطِّعَنَّ أَيۡدِيَكُمۡ وَأَرۡجُلَكُم مِّنۡ خِلَـٰفٍ۬ وَلَأُصَلِّبَنَّكُمۡ فِى جُذُوعِ ٱلنَّخۡلِ وَلَتَعۡلَمُنَّ أَيُّنَآ أَشَدُّ عَذَابً۬ا وَأَبۡقَىٰ
قَالُواْ لَن نُّؤۡثِرَكَ عَلَىٰ مَا جَآءَنَا مِنَ ٱلۡبَيِّنَـٰتِ وَٱلَّذِى فَطَرَنَا‌ۖ فَٱقۡضِ مَآ أَنتَ قَاضٍ‌ۖ إِنَّمَا تَقۡضِى هَـٰذِهِ ٱلۡحَيَوٰةَ ٱلدُّنۡيَآ
إِنَّآ ءَامَنَّا بِرَبِّنَا لِيَغۡفِرَ لَنَا خَطَـٰيَـٰنَا وَمَآ أَكۡرَهۡتَنَا عَلَيۡهِ مِنَ ٱلسِّحۡرِ‌ۗ وَٱللَّهُ خَيۡرٌ۬ وَأَبۡقَىٰٓ

They said: “O Musa! Either you throw first or we be the first to throw?” [Musa] said: “Nay, throw you (first)!” Then behold, their ropes and their sticks, by their magic, appeared to him as though they moved fast. So Musa conceived a fear in himself. We (Allah) said: “Fear not! Surely, you will have the upper hand. “And throw that which is in your right hand! It will swallow up that which they have made. That which they have made is only a magician’s trick, and the magician will never be successful, no matter whatever amount (of skill) he may attain.”

So the magicians fell down prostrate. They said: “We believe in the Lord of Harun and Musa.”

[Fir’aun (Pharaoh)] said: “Believe you in him [Musa (Moses)] before I give you permission? Verily! He is your chief who taught you magic. So I will surely cut off your hands and feet on opposite sides, and I will surely crucify you on the trunks of date-palms, and you shall surely know which of us [I (Fir’aun – Pharaoh) or the Lord of Musa (Allah)] can give the severe and more lasting torment.”

They said: “We prefer you not over the clear signs that have come to us, and to Him (Allah) Who created us. So decree whatever you desire to decree, for you can only decree (regarding) this life of the world. “Verily! We have believed in our Lord, that He may forgive us our faults, and the magic to which you did compel us. And Allah is better as regards reward in comparison to your [Fir’aun’s] reward, and more lasting (as regards punishment in comparison to your punishment).” [Taa Haa. 65-73]

قَالُواْ لَن نُّؤۡثِرَكَ عَلَىٰ مَا جَآءَنَا مِنَ ٱلۡبَيِّنَـٰتِ وَٱلَّذِى فَطَرَنَا‌ۖ

They said: “We prefer you not over the clear signs that have come to us, and to Him (Allah) Who created us…

Meaning, we do not prefer you over what we have been promised of reward and the closeness to that which we have been shown clear signs, showing that Allah alone is the Lord and true deity to be worshipped- The Most Great, The Only Magnificent One – and every other thing that is worshipped besides Allah and considered as a lord is false. It is not possible that we will prefer you over the One who created and brought us into existence prior to our  state of non-existence; therefore:

فَٱقۡضِ مَآ أَنتَ قَاضٍ‌ۖ إِنَّمَا تَقۡضِى هَـٰذِهِ ٱلۡحَيَوٰةَ ٱلدُّنۡيَآ

“decree whatever you desire to decree, for you can only decree (regarding) this life of the world”…

Meaning: do what you promise us, that you will cut off our hands and feet, and crucify us, because it will come to an end regardless of its severity in this worldly life and cannot harm us thereafter when compared to Allah’s punishment for the one who persist upon disbelief, for indeed the punishment will be great and continuous.

This seemed to be their reply to Fir’awn when he said to them:

وَلَتَعۡلَمُنَّ أَيُّنَآ أَشَدُّ عَذَابً۬ا وَأَبۡقَىٰ

“And you shall surely know which of us (I (Fir’aun) or the Lord of Musa (Allah) can give the severe and more lasting torment”.

The statement of the magicians shows that it is incumbent upon a sensible person to compare the enjoyment of this life with the enjoyment of the afterlife, and compare the punishment in this life to punishment in the afterlife.

Then Allah said that the magicians said:

إِنَّآ ءَامَنَّا بِرَبِّنَا لِيَغۡفِرَ لَنَا خَطَـٰيَـٰنَا ۗ

“Verily! We have believed in our Lord, that He may forgive us our faults”…

Meaning: so that Allah may forgive us our disbelief and sins, because Iman expiates disbelief, and repentance wipes away one’s previous sins.

وَمَآ أَكۡرَهۡتَنَا عَلَيۡهِ مِنَ ٱلسِّحۡرِ

“And the magic to which you did compel us”..

Meaning: forgive us the sin of sorcery through which we opposed the truth.

This shows that they did not have a choice in what they did, rather Firawn compelled them. And that which is apparent – and Allah knows best – is that when Musa, peace be upon him, admonished them saying:

وَيۡلَكُمۡ لَا تَفۡتَرُواْ عَلَى ٱللَّهِ ڪَذِبً۬ا فَيُسۡحِتَكُم بِعَذَابٍ۬‌ۖ وَقَدۡ خَابَ مَنِ ٱفۡتَرَىٰ

“Woe unto you! Invent not a lie against Allah, lest He should destroy you completely by a torment. And surely, he who invents a lie (against Allah) will fail miserably”, it did have an effect on them and this is why they debated (regarding whether Musa was upon truth or not), but Fir’awn compelled and forced them to commit their plot. This is why they said what Firawn said before they arrived:

إِنۡ هَـٰذَٲنِ لَسَـٰحِرَٲنِ يُرِيدَانِ أَن يُخۡرِجَاكُم مِّنۡ أَرۡضِكُم بِسِحۡرِهِمَا وَيَذۡهَبَا بِطَرِيقَتِكُمُ ٱلۡمُثۡلَى

Verily! These are two magicians (i.e. Musa and Harun). Their object is to drive you out from your land with magic, and overcome your chiefs and nobles.

So they did that which was made up and forced on them. And maybe what settled in their hearts regarding hatred of opposing the truth with falsehood is that which earned them Allah’s Mercy, Iman and the ability to repent.

وَٱللَّهُ خَيۡرٌ۬ وَأَبۡقَىٰٓ

“And Allah is better as regards reward in comparison to your [Fir’aun’s] reward, and more lasting”.

Meaning: better as reward than what you promised us of status and rank, more lasting in reward and generosity, as opposed to what you [Firawn] say that “And you shall surely know which of us [I (Fir’aun – Pharaoh) or the Lord of Musa (Allah)] can give the severe and more lasting torment]– Meaning, he [Firawn] meant that his punishment is more severe and lasting than Allaah’s punishment.

An Excerpt from Tafseer As-Sadi. Slightly paraphrased