Proofs of Allah's Oneness abound in the Creation of the Heavens and the Earth
Allah reminds us of the creating of the higher and lower worlds,
وَالسَّمَآءَ بَنَيْنَـهَا
(We constructed the heaven.) meaning, `We made it as a high roof, protected from falling,'
بِأَيْدٍ
(with Hands), meaning, with strength, according to `Abdullah bin `Abbas, Mujahid, Qatadah, Ath-Thawri and several others,
وَإِنَّا لَمُوسِعُونَ
(Verily, We are able to extend the vastness of space thereof.) means, `We made it vast and We brought its roof higher without pillars to support it, and thus it is hanging independently.'
وَالاٌّرْضَ فَرَشْنَـهَا
(And We have made the earth a Firash), meaning, `We have made it a resting place for the created,'
Proofs of Allah's Oneness abound in the Creation of the Heavens and Earth
The preceding verses mentioned the reality of the Hereafter and the Judgment Day, and the punishment of those who denied the reality. The present set of verses reaffirm the perfect power of Allah, reminding us about the reality of the Day of Resurrection and allaying the doubt and suspicion of those who deny the reality. It proves the oneness of Allah and reiterates emphatically to believe in the Messenger ﷺ .
بَنَيْنَاهَا بِأَيْدٍ وَإِنَّا لَمُوسِعُونَ (And the sky was built by Us with might, and indeed, We are the One who expands.... 51:47). The word aidin, according to Sayyidna Ibn ` Abbas ؓ ، means strength or power in this context.
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 49–54
The system of our world is a highly meaningful one. This proves that the creation of the present world has been brought about with some high purpose. But we see that man has wrecked disorder on the earth. In the meaningful universe, this meaningless development is incongrous and calls for a world which is free of all evils to come into existence. In the present world provision has already been made for this, i.e. all things in this world come in pairs—in matter, positive and negative particles, in plants male and female and among human beings, men and women. This is the quintessence of the universe: the prevalence of the law of compensating for the shortcomings of any given thing through its pair or complement. This duality is an indication of the possibility of the Hereafter. In other words, the world of Hereafter is the other part which makes up a pair with the present world and this combination makes our world complete.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.