Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(And He it is Who gave you life) when you were very little in the wombs of your mothers, (then He will cause you to die) in young or old age, (and then will give you life (again)) at resurrection after death. (Lo! Man) i.e. the disbeliever Budayl Ibn Warqa' al-Khuza'i (is verily an ingrate) he disbelieves in Allah, resurrection after death as well as in the immolated animals of the Muslims.
And He it is Who gave you life, by originating you, then He will cause you to die, upon the conclusion of your terms [of life], then He will give you life [again], at the Resurrection. Truly man, that is, [truly] the idolater, is very ungrateful, for God’s graces by neglecting to affirm His Oneness.
(Then We made the Nutfah into a clot, then We made the clot into a little lump of flesh) 23:14. It was recorded in the Two Sahihs that between each stage there are forty days. Allah's saying,
فَتُصْبِحُ الاٌّرْضُ مُخْضَرَّةً
(and then the earth becomes green) means, it becomes green after being dry and lifeless. It was reported from some of the people of Al-Hijaz that the land turns green after rainfall. And Allah knows best.
إِنَّ اللَّهَ لَطِيفٌ خَبِيرٌ
(Verily, Allah is the Most Kind and Courteous, Well-Acquainted with all things.) He knows what seeds are in the various regions of the earth, no matter how small they are. Nothing whatsoever is hidden from Him. Each of those seeds receives its share of water and begins to grow, as Luqman said:
("O my son! If it be equal to the weight of a grain of mustard seed, and though it be in a rock, or in the heavens or in the earth, Allah will bring it forth. Verily, Allah is Subtle, Well-Aware.) 31:16 And Allah says:
(And nothing is hidden from your Lord, the weight of a speck of dust on the earth or in the heaven. Not what is less than that or what is greater than that but it is (written) in a Clear Record.) 10:61
لَهُ مَا فِى السَّمَـوَت وَمَا فِى الاٌّرْضِ
(To Him belongs all that is in the heavens and all that is on the earth.) He owns all things, and He has no need of anything besides Himself, everything is in need of Him and in a state of submission to Him.
(And has subjected to you all that is in the heavens and all that is in the earth) 45:13, meaning that all of this is a blessing and out of His kindness.
وَالْفُلْكَ تَجْرِى فِى الْبَحْرِ بِأَمْرِهِ
(and the ships that sail through the sea by His command) That is because He subjugates it to them and makes it easy for them. In the raging sea with its tempestuous waves, the ships sail gently with their passengers and carry them wherever they want to go for trading and other purposes from one land to another, so that they bring goods from here to there, or vice versa, whatever people want or need.
(He withholds the heaven from falling on the earth except by His leave.) If He willed, He could give the sky permission to fall on the earth, and whoever is in it would be killed, but by His kindness, mercy and power, He withholds the heaven from falling on the earth, except by His leave. He says:
إِنَّ اللَّهَ بِالنَّاسِ لَرَءُوفٌ رَّحِيمٌ
(Verily, Allah is for mankind, full of kindness, Most Merciful.) meaning, even though they do wrong. As Allah says elsewhere:
(They will say: "Our Lord! You have made us to die twice, and You have given us life twice!'') 40:11 So how can you set up rivals to Allah and worship others besides Him when He is the One Who is independent in His powers of creation, provision and control of the existence
وَهُوَ الَّذِى أَحْيَاكُمْ
(It is He, Who gave you life,) means, He gave you life after you were nothing, and brought you into existence.
ثُمَّ يُمِيتُكُمْ ثُمَّ يُحْيِيكُمْ
(and then will cause you to die, and will again give you life.) means, on the Day of Resurrection.
إِنَّ الإِنْسَـنَ لَكَفُورٌ
(Verily, man is indeed Kafurun.) meaning, denying.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
Here "the sky" implies the whole of the universe above and below the earth where everything is held in its own place and sphere.
That is, "Though man sees every reality presented by the Prophets, yet he denies it".