All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
Ibn Katheer commented on the verse in reference, saying:
"The verse: {And of his signs is the creation of the heavens and earth and what He has dispersed throughout them of creatures. And He, for gathering them when He wills, is competent.} [Quran 42:29] (And of His signs): the signs which indicate His great might and power. (The creation of the heavens and earth and what He has dispersed throughout them of creatures) means, whatever He has created in them, i.e., in the heavens and the earth. The phrase (of creatures) includes the angels, men, jinn, and all the animals, with their different shapes, colors, languages, natures, races and types. He has distributed them throughout the various regions of the heavens and earth. (And He) means, yet despite all that, (And He, for gathering them when He wills, is competent) means that on the Day of Resurrection, He will gather the first and the last of them and bring all His creatures together in one place, where they will all hear the voice of the caller, and all of them will be seen clearly; then He will judge between them with justice and truth."
Sheikh As-Sa‘di commented on the verse saying:
"One of the signs of His great omnipotence and that He will resurrect the dead and bring them back to life is the creation of the heavens and earth given their grandeur and vastness which indicate His omnipotence and extensive might. The perfection and precision of the creation indicate His wisdom, and the benefits therein indicate His mercy. This proves that He alone is worthy of all forms of worship; none is worthy of worship but Him, and all other deities are false gods. He has spread diverse kinds of creatures from whom human beings benefit and avail themselves in the heavens and earth. He is Able to assemble the whole creation after death for the resurrection and judgment on the Last Day. His limitless power and will prove that He is Able to do so, and this is verified by authentic reports. This has been reported with collectively contiguous chains of narrations by Messengers and documented in their divine books, testifying to this fact."
Allah knows best.