لَّهُ مَا فِي السَّمَاوَاتِ وَمَا فِي الْأَرْضِ
لَّهُ To Him [belongs]
مَا فِي what [is] in
السَّمَاوَاتِ the heavens (feminine plural)*
وَمَا فِي and what [is] in
الْأَرْضِ the earth
*From my own understanding this is in reference to the seven heavens above us more so than the literal sky above us.
There is a distinction between the sky, which is what is above us, the Heavens (i.e. the Quran descended to the lowest heaven during the month of Ramadan and then was revealed in parts throughout the 23 years of the Prophet (saw’s) life, also we know in the seventh heaven the angels make tawaaf around Al-Bait-al-Ma'mur) and finally we have what we refer to as 'paradise' which is the Jannah Allah has created for the believers to dwell in the hereafter.
On a side note, to appreciate what is being said in the verse, Allah says to him belongs what is in the heavens; we know our galaxy, our entire universe, which according to different sources is predicated to be around 13.7 to 180 billion light years wide.
In one narration it is said the size of each of them [i.e. the heavens] in comparison with the succeeding one was like that of a ring thrown into a desert.
Some consider the universe which we are able to measure as the lowest heaven.
لَّهُ مَا فِي السَّمَاوَاتِ I think, now, carries a whole new meaning…!