‘I wrote to Ibn Abbās asking him to write something [pertaining to knowledge] for me and he withheld from me quite a bit, and said: ‘As [if he were] a sincere child, I will write for him something especially suited to his status withholding from him what would not benefit him’. [Ibn Abī Mulaykah] said: ‘So [Ibn Abbās] called for the judgment of Alī [bin Abī Tālib which was a book with which Alī would pass verdicts in Kuffah], and he began to write from it [with respect to the request of Ibn Abī Mulaykah] and he came upon something [not appropriate to the station of Alī regarding the science of verdicts]. So [Ibn Abbās] said: ‘By Allah, Alī did not give judgment according to this unless he was astray’.’  

كَتَبْتُ إِلَى ابْنِ عَبَّاسٍ أَسْأَلُهُ أَنْ يَكْتُبَ لِي كِتَابًا وَيُخْفِي عَنِّي فَقَالَ وَلَدٌ نَاصِحٌ أَنَا أَخْتَارُ لَهُ الأُمُورَ اخْتِيَارًا وَأُخْفِي عَنْهُ قَالَ فَدَعَا بِقَضَاءِ عَلِيٍّ فَجَعَلَ يَكْتُبُ مِنْهُ أَشْيَاءَ وَيَمُرُّ بِهِ الشَّىْءُ فَيَقُولُ وَاللَّهِ مَا قَضَى بِهَذَا عَلِيٌّ إِلاَّ أَنْ يَكُونَ ضَلَّ