Need To Pray Nafal Salah
Salah and its mandatory rakaat are transmitted to us through Sunnah, not through Quran. Therefore, you will not find any such principle in Quran. However, a general principle on Nafal Ibadah has been mentioned in Quran: إِنَّ الصَّفَا وَالْمَرْوَةَ مِن شَعَآئِرِ اللّهِ فَمَنْ حَجَّ الْبَيْتَ أَوِ اعْتَمَرَ فَلاَ جُنَاحَ عَلَيْهِ أَن يَطَّوَّفَ بِهِمَا وَمَن تَطَوَّعَ خَيْرًا فَإِنَّ اللّهَ شَاكِرٌ عَلِيمٌ إِنَّ الَّذِينَ يَكْتُمُونَ مَا أَنزَلْنَا مِنَ الْبَيِّنَاتِ وَالْهُدَى مِن بَعْدِ مَا بَيَّنَّاهُ لِلنَّاسِ فِي الْكِتَابِ أُولَـئِكَ يَلعَنُهُمُ اللّهُ وَيَلْعَنُهُمُ اللَّاعِنُونَ(2 :158-159) Safa and Marwah are indeed God’s symbols. So it shall be no offence for those who come for hajj or ‘umrah of this Sacred House to walk around them. [In fact, this a virtuous deed] and He who does a virtue of his own will God will accept it and is fully aware of it . Those who conceal the clear proofs and the guidance We have revealed [in this matter]even though We had openly proclaimed them for these people in our Book, it is they who shall be cursed by God and cursed by those who curse. (2:158-159)