Correction of the name: In the manuscripts this name was corrupted to "Hafs" (Z) and "Hamzah" (S, A), and it is likewise in "Ithaf al-Maharah" by al-Hafiz Ibn Hajar (12526). All of this is corruption. The correct name is "Khumayr bin Malik", as in manuscript (B); it is also said "Khamr". His biography is in al-Bukhari's "al-Tarikh al-Kabir" (3/ 227), Ibn Abi Hatim's "al-Jarh wa al-Ta'dil" (3/ 391), al-Daraqutni's "al-Mu'talif wa al-Mukhtalif" (2/ 671-672), al-Khatib al-Baghdadi's "al-Muttafiq wa al-Muftariq" (2/ 862) and others. Some of them mentioned this hadith of his from Ibn Mas'ud.

Grading of the hadith and chain: The hadith is "sahih", and this chain is "hasan" on account of Khumayr bin Malik (he is a senior Successor, Ibn Hibban mentioned him in "al-Thiqat", and he has been corroborated). Sufyan is al-Thawri and Abu Ishaq is 'Amr bin Abdullah al-Sabi'i.
Reference / Source: It was recorded by Ahmad (6/ 3697, 3846, 4218) via Waki' from Sufyan, with this same chain. In it: "and Zayd had a forelock (i.e. was a boy) at the Qur'an school."

Reference / Source: Ahmad (7/ 3929) also recorded it via Isra'il from Abu Ishaq, except that Zayd is not mentioned in it.

Reference / Source: In a narration similar to the author's, al-Nasa'i (9278) and Ibn Hibban (7064) recorded it via al-A'mash from Abu Ishaq from Hubayrah bin Yarim from Ibn Mas'ud.

Reference / Source: Al-A'mash has another chain for it: it was recorded by Ahmad (7/ 3906), al-Bukhari (5000), Muslim (2462) and al-Nasa'i (7943, 9279) via him from Abu Wa'il Shaqiq bin Salamah from Ibn Mas'ud. Al-Bukhari, Muslim and al-Nasa'i (in the first place) did not mention Zayd in it.

Reference / Source: Ahmad recorded it via Zirr bin Hubaysh (6/ 3599, 7/ 4330) and via a man from Hamdan among the companions of Ibn Mas'ud (6/ 3845), both from Ibn Mas'ud, and neither of them mentioned Zayd. (See the next narration.)