The authenticity of a hadith regarding the specification of Allah’s Greatest Name

Question:
Honorable Shaykh, may Allah grant you success. A questioner says: Is there a hadith from the Messenger of Allah (peace and blessings be upon him) specifying Allah’s Greatest Name, by which, if He is called upon, He responds?

Answer:
No hadith has been established regarding the specification of Allah’s Greatest Name, because Allah concealed it among His names so that the Muslim would call upon Allah by all His names in order to attain much reward. Just as He concealed the hour of Friday, and just as He concealed the Night of Decree, so that the servants would strive to seek reward, working throughout the month, praying throughout the month, and making du'a' on every Friday. Allah’s concealment of the Greatest Name is of this nature: He concealed them so that the servants would strive in calling upon Allah by all His names. Allah has the most beautiful names, so call upon Him by them; one does not restrict oneself to a single name. Yes.