Is it established that "Al-Hayiyy" (the Modest/Shy) and "As-Sittir" (the Concealer) are among the Most Beautiful Names of Allah, or are they merely attributes of Allah? And how can one supplicate using them if they are among the Most Beautiful Names of Allah?

"Al-Hayy" (The Modest/Shy) and "As-Sattir" (The Concealer/Coverer) are two established names for Allah the Almighty. It was narrated from the Prophet, peace and blessings be upon him, that he said: "Indeed, Allah, the Mighty and Majestic, is Modest and Concealing; He loves modesty and concealment," and Al-Albani graded it as authentic. Scholars have differed regarding their inclusion among the Beautiful Names of Allah. Some affirmed them, such as Al-Halimi, Al-Bayhaqi, and Ibn Al-Qayyim, while others excluded them, such as Ibn Hazm and Al-Khattabi. In any case, modesty and concealment are two attributes firmly established for Allah, befitting His perfection. Their meanings are that Allah is exceedingly modest from disgracing His servants and a Concealer of their faults, and He loves modesty and concealment from them. It is permissible to supplicate using these two names, such as saying: "O Hayy, O Sattir, conceal me," or "O Allah, You are Hayy and love modesty, Sattir and love concealment, so conceal me." And among the greatest means of seeking closeness is for the servant to manifest these two attributes in his life, so he does not expose people's faults and strives to conceal them, because Allah rewards the servant according to the attributes with which he treats His creation.