Allah tells us why He saved the Children of Israel from Fir`awn and his people. He tells us how he saved them. Allah commanded Musa and his brother Harun to take houses for their people in Egypt,

﴿وَاجْعَلُواْ بُيُوتَكُمْ قِبْلَةً﴾

(and make your dwellings as places for your worship,) Al-`Awfi reported that Ibn `Abbas said, while interpreting this Ayah: "The Children of Israel said to Musa, `We cannot offer our prayers in public in front of Fir`awn's people.' So Allah permitted them to pray in their houses. They were commanded to build their houses in the direction of the Qiblah.'' Mujahid commented,

﴿وَاجْعَلُواْ بُيُوتَكُمْ قِبْلَةً﴾

(and make your dwellings as places for your worship,) When Banu Israel feared that Fir`awn might kill them in their gatherings at their temples, they were commanded to take their houses as places of worship. The houses should be facing the Qiblah and the prayer could be in secret.'' This was stated by Qatadah and Ad-Dahhak as well.

﴿وَقَالَ مُوسَى رَبَّنَآ إِنَّكَ ءاتَيْتَ فِرْعَوْنَ وَمَلاّهُ زِينَةً وَأَمْوَالاً فِى الْحَيَوةِ الدُّنْيَا رَبَّنَا لِيُضِلُّواْ عَن سَبِيلِكَ رَبَّنَا اطْمِسْ عَلَى أَمْوَلِهِمْ وَاشْدُدْ عَلَى قُلُوبِهِمْ فَلاَ يُؤْمِنُواْ حَتَّى يَرَوُاْ الْعَذَابَ الاٌّلِيمَ - قَالَ قَدْ أُجِيبَتْ دَّعْوَتُكُمَا فَاسْتَقِيمَا وَلاَ تَتَّبِعَآنِّ سَبِيلَ الَّذِينَ لاَ يَعْلَمُونَ ﴾

(88. And Musa said: "Our Lord! You have indeed bestowed on Fir`awn and his chiefs splendor and wealth in the life of this world, our Lord! That they may lead men astray from Your path. Our Lord! Destroy their wealth, and harden their hearts, so that they will not believe until they see the painful torment.'') (89. Allah said: "Verily, the invocation of you both is accepted. So you both keep to the straight way, and follow not the path of those who know not.'')