As-Salaam alaikum,
Ayat 109 of Surat Kahfi of the Holy Qur'an (18:109) reads:--

"Say [O Muhammad]: If the ocean were ink (wherewith to write out) the
words of my Lord, sooner would the ocean be exhausted than would the
words of my Lord, even if we added another ocean like it for its aid."

This means the secrets coming from the letters, words and verses/ayats of the Holy Qur'an are overwhelmingly so much, that if you keep writing from the beginning of the dunya to the end and using the ocean as ink, the ocean will finish and still the interpretation of the Holy Qur'an will not finish. Whatever ayat or word of the Qur'an we read has many serets... some we/you know, but several such secrets remain veiled from us, but they are there... the Qur'anic overflowing secrets never end.