Muwatta Malik · Hadith 480

وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، مَكَثَ عَلَى سُورَةِ الْبَقَرَةِ ثَمَانِيَ سِنِينَ يَتَعَلَّمُهَا ‏.‏

Yahya related to me from Malik that he had heard that it took Abdullah ibn Umar eight years to learn Surat al-Baqara. (Sura)

Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).