How authentic is the Qudsi Hadith: "Whoever is returned to a stray, I shall record him under the leg of the Throne as a master, and whoever I record as a master, I shall never punish him," which was mentioned by the Friday preacher?

This Hadith has no origin, and its utmost is that it is taken from the People of the Book. It has been narrated in several accounts from Shumayt ibn Ajlan, Al-Hasan, and Al-Harith al-Muhasibi that Allah revealed to David (peace be upon him): "If you rescue a perishing soul from its perdition, I will name you a jahbadh," or "Associate with people and endure their harm, perhaps you will return a bewildered person from their bewilderment, or a drunkard from their intoxication, then I will record you with Me as a jahbadh," or "For a servant, whom the love of this world has intoxicated, to be guided by your hands, I will name you with Me as a jahbadh, and whoever is a jahbadh will not experience poverty or loneliness." It appears that this discourse is taken from the books of the People of the Book, and it is sufficiently replaced by the Prophet's (peace and blessings of Allah be upon him) Hadith to Ali (may Allah be pleased with him) on the Day of Khaybar: "By Allah, for Allah to guide a single man through you is better for you than possessing red camels."