The Opening Verse of the Holy Quran
و في الحديث عن مولى الأمة و إمامها أمير المؤمنين علي بن أبي طالب (عليه السلام) أن عبدالله بن عباس جاءه (عليه السلام) يسأله عن تفسير القرآن، فوعده بالليل، فلما حضر قال: «ما أول القرآن؟». قال: الفاتحة. قال: «و ما أول الفاتحة؟» قال: بسم الله. قال: «و ما أول بسم الله؟». قال: بسم. قال: «و ما أول بسم؟». قال: الباء، فجعل (عليه السلام) يتكلم في الباء طول الليل، فلما قرب الفجر قال: «لو زادنا الليل لزدنا
And in the Hadeeth, from Master-asws of the community and its Imam-asws Amir-Al-Momineen Ali-asws Bin Abu Talib-asws that: ‘Abdullah Bin Abbas came to him-asws asking him-asws about interpretation of the Quran. So he-asws gave him an appointment at night. So when he came, he said, ‘What is the first (start) of the Quran?’ He-asws said: ‘Al-Fatiha’. He said, ‘And what is the start of Al-Fatiha?’ He-asws said: ‘Bismillah’ (In the Name of Allah-azwj)’. He said, ‘And what is the start of Bismillah?’ He-asws said: ‘Bism’ (In the Name). He said, ‘And what is the start of ‘Bism’?’ He-asws said: ‘The ‘Ba’. Andhe-asws went on to speak about the ‘Ba’ for most of the night. When it was near to the dawn, he-asws said: ‘Had the night increased for us, I-asws would increase more (of this explanation)’.[1]
[1] (الصراط المستقيم 1: 219.)