Said the Heaven before earth:
Refers to the meaning of which is that the heavens and the Earth often mention in the context of the evidence on the existence of God and his greatness and his ability and his oneness ....etc
And it is known that the verses in heaven is greater than Earth for heaven's capacity, greatness, the planets, sun, height and lack of need to pillars to raises it ... other wonders.
So said the sky before the earth is better evidence to the greatness of God, because it have more information.
while in the said the Earth before heaven :
" قُلْ أَرَأَيْتُمْ شُرَكَآءَكُمُ ٱلَّذِينَ تَدْعُونَ مِن دُونِ
ٱللَّهِ أَرُونِي مَاذَا خَلَقُواْ مِنَ ٱلأَرْضِ أَمْ لَهُمْ شِرْكٌ فِي
ٱلسَّمَاوَاتِ ... "
Say: "Look at the compeers you invoke apart from God. Show me, what
of the earth have they created, or what share have they in the
heavens? .... [Fatir:40]
In this verse began by mentioning the Earth; that in the context incapacitate of humans to creation and participation, and earth is much easier than the sky, so began in the earth to exaggerate the statement of disability;
because who was deficit of easier two things, he was more deficit
while in this verse:
تَنزِيلًا مِّمَّنْ خَلَقَ الْأَرْضَ وَالسَّمَاوَاتِ الْعُلَى
"To Him belongs what is in the heavens and what is on the earth and
what is between them and what is under the soil."
Have came in meaning, that this Koran, which came to Mohammed is from Allah, the Lord and sovereign of all things capable of what he wants, who created the earth with its intensity and the creation of the heavens with its height.
So here came the verse in the context of the statement evidence of humans on the existence of God and his greatness,so said the Earth before heaven to closeness it to our understanding of God's power and greatness in the land.