As-Salaam alaikum,

"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 word of my Lord, even if we added another
ocean like it for its aid."
(Surat Kahfi- 18:109)

This means the secrets coming from the letters, words and verses of the Holy Qur'an are overwhelmingly so much, that if you keep writing from the beginning of 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.

So, whatever ayat/verse or word of the Qur'an you read has many secrets... some you/we know, but several such secrets remain veiled from us, but they are there.

It is like in a box of medicine-- there is a general, bulleted description of it, but at the end of the brochure is the detailed breakdown of 2 or 3 pages telling you this, this, this, the chemistry of that drug. Similarly, if you read any word of the Holy Qur'an, the whole package has to come with it-- overflowing secrets that never end! So when we read the Qur'an, we get the reward of what we read, along with the whole package, and that cannot be described.