“If you speak aloud, He surely knows what is secret and what is even more hidden. Allah—there is no deity worthy of worship except Him. To Him belong the Most Beautiful Names. Has the account of Moses reached you?”
“If you speak aloud”—that is, if you make it public (1)—“He surely knows what is secret and what is even more hidden.” Al-Hasan said: “The secret” is what a person confides to another, while “what is even more hidden” is what he conceals within himself.
Ibn ‘Abbas and Sa‘id ibn Jubayr said: “The secret” is what you conceal within yourself, while “what is even more hidden” than the secret is what Allah, Exalted is He, will later place in your heart—something which you do not know you will speak to yourself about. For you know what you conceal today, but you do not know what you will conceal tomorrow; whereas Allah knows what you concealed today and what you will conceal tomorrow.
‘Ali ibn Abi Talhah narrated from Ibn ‘Abbas: “The secret” is what the son of Adam conceals within himself, while “what is even more hidden” is that which remains hidden from him regarding what he will do before he himself comes to know it.
Mujahid said: “The secret” is the deed that you conceal from people, and “what is even more hidden” is the whispering of the soul.
It was also said: “The secret” is firm resolve, while “what is even more hidden” is what passes through the heart but has not been resolved upon.
Zayd ibn Aslam said: “He knows the secret (2) and what is even more hidden”—that is, He knows the secrets of His servants, as well as His own secret, which He has concealed from His servants, so that no one knows it (3). He then declared His own oneness, saying: “Allah—there is no deity worthy of worship except Him. To Him belong the Most Beautiful Names.”
His words, Exalted is He, “Has the account of Moses reached you?” mean: It has indeed reached you. This is a rhetorical question intended as an affirmation.