Musannaf Ibn Abi Shayba 22:10

Abu Usama narrated to us, from Umar ibn Hamza, who said: Salim informed me that Zayd ibn Thabit consulted Umar regarding the compilation of the Quran, but he refused him, saying: "You are a people who commit grammatical errors." Then he consulted Uthman, and he gave him permission.