وَعَنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ أَنَّهُ قَالَ: إِنَّ لِكُلِّ شَيْءٍ سَنَامًا وَإِنَّ سَنَامَ الْقُرْآنِ سُورَةُ الْبَقَرَةِ وَإِنَّ لِكُلِّ شَيْءٍ لُبَابًا وَإِنَّ لباب الْقُرْآن الْمفصل. رَوَاهُ الدَّارمِيّ

37, 45, 47, 48, 50, 61, 67, and 93. The name is most appropriately explained as meaning that this is the section of the Qur’ān which contains many shorter sūras. Dārimī transmitted it.