Al-A'mash relates that Shaqiq (Abu Wa'il) was mentioning the Companions of the Prophet (peace and blessings be upon him) but did not mention Ibn Mas'ud. I said to him: I see that you are not mentioning Ibn Mas'ud?! He replied: "He is a man over whom I do not give preference to anyone." This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.