Hadith 2179

‘Abdallāh b. Mas'ūd said, “Everything has a hump, and the hump of the Qur’ān is sūra al-Baqara. Everything has a kernel, and the kernel of the Qur’ān is al-Mufassal.* *A title given to the sūras from 49 to the end, but several other sūras are also mentioned: 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.

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

Reference: 5621790
In-book reference: Book 8, Hadith 2179
Hadith 2179 - The Excellent Qualities of the Qur'an - Mishkat al-Masabih - Sunnah.com