Allah is The Most Knowledgeable
The first of them is Allah’s grand gift of the teaching of the Qur’an:

{The Most Merciful. Taught the Qur’an.} (55:1-2)

That is the first subject matter, and how the Qur’an is catered to the nature of human beings and how it resonates with its inner selves, and how that is an expression of Allah’s love, care and mercy.

That is why it is predicated by Ar-Rahman. Taught the Qur’an, not Al-Aleem (The Most Knowledgeable) taught the Qur’an.

No, it is the One who is exceedingly loving and merciful and caring is the One who taught the Qur’an.

So Allah’s act of teaching the Qur’an is an act of love and care and mercy. That’s the first passage.

Pairs
In this surah, Allah (SWT) addresses both human beings and the jinn.

That is something unique which Allah does in this surah, and throughout the surah everything is in pairs.

Just like a pair of species are being talked to (human beings and jinn), Jannahs are in pairs, so He talks about them twice, He talks about gardens twice,…

Across the board, there is this theme of pairs moving along.

Repetition
The thing about repetition in this surah, the first thing I want you to know is that repetition is done for certain purposes.

It is not just for style or for emphasis, but it has a greater rhetorical and communicative purpose. And that purpose is actually the expression of anger.

How much more ungrateful can you be?

How much more ungrateful can you be?…

It is this progression of Allah’s anger towards people who just completely reject the idea of gratitude, who look around them and don’t feel any need or compulsion to being thankful for what they have been given.

And that’s how the ayat progress…

But then, that same exact phrase as you get to the latter half of the surah where Allah starts talking about Heaven, and the people of Heaven and He says:

{So which of the favors of your Lord would you deny?} (55:47)

Here He imposes His favor on those He has benefited, not just in this world, but in the next also, so as that same phrase gets more and more intense as it builds up in its intensity in the first half of the surah, it actually starts declining and gets softer and more and more loving as an expression of Allah’s love in the latter half of the surah.