Bukhari Vol. 1, Book 003, Hadith Number 121.
Narated By Abu Huraira : I have memorized two kinds of knowledge from Allah's Apostle . I have propagated one of them to you and if I propagated the second, then my pharynx (throat) would be cut (i.e. killed).
This is a non Quranic concepts and an attempt to depict the mission of RASOOL (s) as a failure as Qur’an says
5:67 O Messenger! Make known all that your Lord has revealed to you. If you do not do it, then you have not fulfilled your duty of conveying His message at all. God will protect you from people. Remember that God does not step in to guide those who refuse to acknowledge the truth.
ُ29:18 And if you reject (the message), so did communities before you (and suffered the consequences). The duty of the Messenger is only to convey the message clearly and publicly. [Balaaghil Mubeen = Convey clearly, openly, publicly]
Mr.Badar , I request you to go through the following verses of Qur’an and please don’t support the Non Qur’anic concept of concealed meaning/Secret Knowledge, created to alter the central aims of the message .
22:52 Yet whenever We sent a Messenger or Prophet before you, Satan (satanic people) tried to confound the central aims of the message. But God, renders null and void all the aspirations Satan had. And God makes His messages clear in and by themselves. God is All Knower, Wise.
[Satanic people then tried to alter his teachings after he passed on. God sent another Messenger to restore the purity of His messages. Then, God revealed His Final message and Himself guaranteed its accuracy and preservation. 5:48, 6:113-116, 15:9, 16:101, 22:52]
22:53 (God allows) these satanic people to advance their aspirations so that He might make this conspiracy a test for people and distinguish (the true believers in the Divine revelation) from those who have a disease in their hearts and who are hardened of heart. Surely, those who relegate the Divine revelation in favor of human aspirations create great schism and sectarianism. [Zulm = Displacing something from its rightful place = Oppression = Violation of human rights = Relegation of the truth = Wrongdoing. 2:53]
22:54 Those who have been given knowledge, will recognize that this (Qur’an) is the truth from your Lord, and so they accept it. Then their hearts are made humble to it. God Himself is the Guide of those who choose to believe, to a straight way. [5:48, 15:19]
22:55 And those who reject faith will not cease to remain in suspense until the Hour suddenly comes upon them, or there comes to them the suffering of a barren day (devoid of all hope).
A Kindergarten Student of Qur'an