اللَّهُ نُورُ السَّمَاوَاتِ وَالْأَرْضِ ۚ مَثَلُ نُورِهِ كَمِشْكَاةٍ فِيهَا مِصْبَاحٌ ۖ الْمِصْبَاحُ فِي زُجَاجَةٍ ۖ الزُّجَاجَةُ كَأَنَّهَا كَوْكَبٌ دُرِّيٌّ يُوقَدُ مِن شَجَرَةٍ مُّبَارَكَةٍ ...

This is a metaphor with many layers of meaning. ‘Light’ symbolizes the guidance of God Almighty. ‘Niche’ is man’s heart and ‘lamp’ is faith (iman), sheltered in that niche. The image is elaborated by two more points of reference: ‘crystal of star-like brilliance’ and ‘luminous oil’. Faith, already compared to a ‘lamp’ standing in the ‘niche’ of the human heart, is safe and well protected from any external influence by the ‘crystal’ or the walls of the niche (human heart). The ‘luminous oil’ filling the lamp and ready to be lit at any moment, speaks of the eagerness with which faith waits for the Truth to appear before it, so that it may accept it without the slightest delay and sets itself ablaze. The fact is that the only source of light in this universe is God. All receive light and guidance from this source alone. Furthermore, God instilled an intense longing for the Truth in the very nature of man. This desire is very strong and, if not diluted, constantly demands gratification. By nature, man’s receptivity to Truth is so immense and inflames so easily that it may be compared to petrol, which flares up as soon as a spark comes in contact with it. A seeker is one who has not let his natural instincts become impaired, so that, the moment he hears the genuine call for the acceptance of Truth, his instincts are aroused. The light of guidance coupled with the light of nature then illuminates his entire existence.

— Source: Tazkirul Quran (Maulana Wahiduddin Khan) via Quran.com (24:35)