Reminders from Surah Al-Qasas— how were the oppressed given leadership and victory over the oppressors and corrupters in the land?! [Imaam Shanqeeti Explains]
Allaah (The Most High) said:
وَنُرِيدُ أَن نَّمُنَّ عَلَى ٱلَّذِينَ ٱسۡتُضۡعِفُواْ فِى ٱلۡأَرۡضِ وَنَجۡعَلَهُمۡ أَٮِٕمَّةً۬ وَنَجۡعَلَهُمُ ٱلۡوَٲرِثِينَ
وَنُمَكِّنَ لَهُمۡ فِى ٱلۡأَرۡضِ وَنُرِىَ فِرۡعَوۡنَ وَهَـٰمَـٰنَ وَجُنُودَهُمَا مِنۡهُم مَّا ڪَانُواْ يَحۡذَرُونَ
”And We wished to do a favour to those who were weak (and oppressed) in the land, and to make them rulers and to make them the inheritors; And to establish them in the land, and We let Fir’aun (Pharaoh) and Haman and their hosts receive from them that which they feared.” [28:5-6]
Imaam Shanqeeti (rahimahullaah) said: We have already stated that His (Allaah’s) statement in this ayah [وَنُرِيدُ أَن نَّمُنَّ عَلَى ٱلَّذِينَ ٱسۡتُضۡعِفُواْ فِى ٱلۡأَرۡضِ And We wished to do a favour to those who were weak (and oppressed) in the land] is the (intended meaning) in His (other) statement:[وَتَمَّتۡ كَلِمَتُ رَبِّكَ ٱلۡحُسۡنَىٰ عَلَىٰ بَنِىٓ إِسۡرَٲٓءِيلَ And the fair Word of your Lord was fulfilled for the Children of Israel (7:137)].
And He (Allaah) did not clarify in (the ayah 28:5) the reason for making them (i.e. Bani Israa’eel) leaders—that is: Leaders to good and callers to Him (i.e. to the path of Allaah). Likewise, He (Allaah) did not clarify the reason for making them inheritors, but He (The Most High) clarified all of that in other places (in the Qur’aan). So He (Allaah) clarified the reason for making them leaders in His saying:
[وَجَعَلۡنَا مِنۡہُمۡ أَٮِٕمَّةً۬ يَہۡدُونَ بِأَمۡرِنَا لَمَّا صَبَرُواْۖ وَڪَانُواْ بِـَٔايَـٰتِنَا يُوقِنُونَ –And We made from among them (Children of Israel), leaders, giving guidance under Our Command, when they were patient and used to believe with certainty in Our Ayat (proofs, evidences, verses, lessons, signs, revelations, etc.)].
[And with regards to His (Allaah) saying: وَأَوۡرَثۡنَا ٱلۡقَوۡمَ ٱلَّذِينَ كَانُواْ يُسۡتَضۡعَفُونَ مَشَـٰرِقَ ٱلۡأَرۡضِ وَمَغَـٰرِبَهَا- And We made the people who were considered weak to inherit the eastern parts of the land and the western parts thereof….] He clarified what He made them inherit, saying: [كَمۡ تَرَكُواْ مِن جَنَّـٰتٍ۬ وَعُيُونٍ۬ — How many of gardens and springs do they [Fir’aun’s (Pharaoh) people] left]. [وَزُرُوعٍ۬ وَمَقَامٍ۬ كَرِيمٍ۬–And green crops (fields etc.) and goodly places] [وَنَعۡمَةٍ۬ كَانُواْ فِيہَا فَـٰكِهِين– And comforts of life wherein they used to take delight!] [كَذَٲلِكَۖ وَأَوۡرَثۡنَـٰهَا قَوۡمًا ءَاخَرِين– Thus (it was)! And We made other people inherit them (i.e. We made the Children of Israel to inherit the kingdom of Egypt) [44:25-28]
And (also) His (The Most High) saying: [فَأَخۡرَجۡنَـٰهُم مِّن جَنَّـٰتٍ۬ وَعُيُونٍ۬– So, We expelled them from gardens and springs] [وَكُنُوزٍ۬ وَمَقَامٍ۬ كَرِيمٍ۬ — Treasures, and every kind of honourable place][ كَذَٲلِكَ وَأَوۡرَثۡنَـٰهَا بَنِىٓ إِسۡرَٲٓءِيلَ– Thus [We turned them (Pharaoh’s people) out] and We caused the Children of Israel to inherit them] [26:57-59] 
[وَنُرِىَ فِرۡعَوۡنَ وَهَـٰمَـٰنَ وَجُنُودَهُمَا مِنۡهُم مَّا ڪَانُواْ يَحۡذَرُون ] [And We let Fir’aun (Pharaoh) and Haman and their hosts receive from them that which they feared] for indeed they were informed that they would be destroyed through the hands of a man of Bani Israa’eel, so they were afraid of them. However Allaah made them received what they feared. 
Imaam Sadi (rahimahullaah) said:
If Allaah wishes that an affair (should take place); He makes the means to it easy and makes its paths distinct. 
[Ref 1: ‘Adwaa Al-Bayaan’ of Imaam Shanqeeti (rahimahullaah). Vol 6. Page 282]
[Ref 2: ‘Zaadul Maseer’ of Imaam Ibnul Jawzi (rahimahullaah). Page 1057]
[Ref 3: Tayseer Al-Kareem Ar-Rahmaan Fee Tafseer Kalaam Al-Mannaan’ of Imaam Sadi. Page: 582. Publisher: Daar Ibn Hazm]