Shaddad bin Ma'qil and I entered upon Ibn ʿAbbas. Shaddad bin Ma'qil asked him, "Did the Prophet ﷺ leave anything (besides the Qur'an)?" He replied. "He did not leave anything except what is Between the two bindings (of the Qur'an)." Then we visited Muhammad bin Al-Hanafiyya and asked him (the same question). He replied, "The Prophet ﷺ did not leave except what is between the bindings (of the Qur'an).  

لَهُ شَدَّادُ بْنُ مَعْقِلٍ أَتَرَكَ النَّبِيُّ ﷺ مِنْ شَىْءٍ قَالَ مَا تَرَكَ إِلاَّ مَا بَيْنَ الدَّفَّتَيْنِ قَالَ وَدَخَلْنَا عَلَى مُحَمَّدِ ابْنِ الْحَنَفِيَّةِ فَسَأَلْنَاهُ فَقَالَ مَا تَرَكَ إِلاَّ مَا بَيْنَ الدَّفَّتَيْنِ