Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(That) the power that enables you to acknowledge and know (is because Allah, He is the True) is because the worship of Allah is the Truth, and that Allah is the Strong, (and that whereon they call) they worship (instead of Him) instead of Allah, (it is the false) it is flimsy, (and because Allah, He is the High) Higher than everything, (the Great) Greater than everything.
That, help, also, is because God, He is the Truth, the Established [Truth], and what they call on (yad‘ūna; also read tad‘ūna, ‘you call on’), [what] they worship, besides Him, namely, idols, that is the False, the transient, and because God, He is the High, the One [supreme] above all things in His power, the Great, besides Whom all things are insignificant.
(Say: "O Allah! Possessor of the power, You give power to whom You will, and You take power from whom You will, and You endue with honor whom You will, and You humiliate whom You will. In Your Hand is the good. Verily, You are able to do all things. You make the night to enter into the day, and You make the day to enter into the night, You bring the living out of the dead, and You bring the dead out of the living. And You give wealth and sustenance to whom You will, without limit.) 3:26-27 The meaning of "merging'' the night into the day and the day into the night is that the one encroaches upon the other, and vice versa. Sometimes the night is long and the day is short, as in winter, and sometimes the day is long and the night is short, as in summer.
وَأَنَّ اللَّهَ سَمِيعٌ بَصِيرٌ
(And verily, Allah is All-Hearer, All-Seer.) He hears what His servants say, and He sees them, nothing about them or their movement is hidden from Him whatsoever. When Allah tells us that He is controlling the affairs of all that exists, and that He judges, and there is none to reverse His judgement, He says:
ذلِكَ بِأَنَّ اللَّهَ هُوَ الْحَقُّ
(That is because Allah -- He is the Truth,) meaning, the true God, besides Whom no one deserves worship. He is the Possessor of the greatest sovereignty; whatever He wills happens and whatever He does not will does not happen. Everything is in need of Him and submits to Him.
وَأَنَّ مَا يَدْعُونَ مِن دُونِهِ هُوَ الْبَـطِلُ
(and what they invoke besides Him, it is false.) meaning, the idols and false gods. Everything that is worshipped instead of Him -- may He be exalted -- is false, because it can neither bring benefit nor cause harm.
وَأَنَّ اللَّهَ هُوَ الْعَلِىُّ الْكَبِيرُ
(And verily, Allah -- He is the Most High, the Most Great.) This is like the Ayat:
وَهُوَ الْعَلِىُّ الْعَظِيمُ
(and He is the Most High, the Most Great) 42:4
(the Most Great, the Most High) 13:9. Everything is subject to His might and power; there is no God except Him and no Lord besides Him, because He is the Almighty and there is none mightier than He, the Most High and there is none higher than He, the Most Great and there is none greater than He. Exalted, sanctified, and glorified be He far above all that the evildoers say.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
"So it is" (as stated in the preceding paragraph) because Allah is the Ruler of the universe and has the power to give punishments and rewards to those who deserve them.
The fact that "Allah brings forth.........day" is a proof that He is the Master, Sovereign and Ruler of the universe. But the deeper meaning of the verse is that Allah, Who is able to bring forth the light of the day out of the darkness of the night, has the power to bring out the light of the Truth out of the darkness of disbelief and ignorance, and the light of justice out of the darkness of tyranny.
He hears everything and sees everything and is not unaware of anything.
As Allah is in fact the Sovereign of the universe, His worshipers will surely attain true success and the worshipers of false gods will meet with utter failure.
This verse has a deeper meaning also, though apparently it merely declares that Allah alone has the power to send down rain which makes the land green. The deeper meaning is that the rainfall of the blessed Revelation will, in the near future, turn the barren land of Arabia into a garden of knowledge, morality and bring forth a high and righteous civilization.
The original word Latif in the Text has no equivalent in English. The word "subtle" has not been used because of its bad associations. Latif implies that Allah fulfills His designs in such fine ways that it is difficult to understand them till they become real and apparent.
As He is fully aware of everything, He knows how to conduct the affairs of His Kingdom.
He alone is "All-Sufficient" and does not stand in need of anyone in any way. He is "All-praiseworthy" because all praise belongs to Him alone whether anyone praises Him or not.