Ma'dikarib (may Allah have mercy on him) said: We came to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) and asked him about the letters "Ta Sin Mim" of Surah al-Shu'ara. He said: "It is not with me; rather, go to the one who took it from the Messenger of Allah (peace and blessings be upon him). You must go to Abu Abdullah Khabbab bin al-Aratt."
Hadith Referenceالمعجم الكبير للطبراني / باب الخاء / 3601