Is it true that Ibn Mas'ud (may Allah be pleased with him) said: "O Zayd ibn Wahb, do not abandon, when it is Friday, praying upon the Prophet (peace and blessings be upon him) a thousand times, saying: 'O Allah, bless the unlettered Prophet'"?

The scholars of Hadith have not issued a ruling of sahih (authentic), hasan (good), or da'if (weak) on the chain of narration (isnad) of the mawquf (stopped) narration attributed to Ibn Mas'ud, may Allah be pleased with him, which mentions praying upon the Prophet, peace and blessings be upon him, a thousand times on Friday. Its chain includes Zuhair ibn Abbad, about whom there is differing opinion, and Al-A'mash is a mudallis (one who conceals defects in narrations) and narrated this isnad using the 'an'ana (from so-and-so) form. However, the legitimacy of increasing prayers upon the Prophet, peace and blessings be upon him, on Friday is established by authentic marfu' (attributed to the Prophet) hadiths, such as the hadith of Aws ibn Aws, which encourages increasing prayers upon him, peace and blessings be upon him, on Friday, for in it, the prayers of his Ummah are presented to him.