And indeed We created the heavens and the earth and all that between them in six Days and nothing of fatigue touched Us.
is emphasis on the Resurrection because He Who is able to create the heavens and earth without fatigue, then surely He is able to resurrect the dead.
Qatadah said,
"The Jews, may Allah's curses descend on them, said that Allah created the heavens and earth in six days and then rested on the seventh day, which was the Sabbath. This is why they call it a holiday. Allah the Exalted then sent down denial of their statement and false opinion."
Allah said,
وَمَا مَسَّنَا مِن لُّغُوبٍ
(and nothing of fatigue touched Us).
indicating that no sleep, exhaustion or weariness affects Him. Allah the Exalted the Blessed said in other Ayat,
أَوَلَمْ يَرَوْاْ أَنَّ اللَّهَ الَّذِى خَلَقَ السَّمَـوَتِ وَالاٌّرْضِ وَلَمْ يَعْىَ بِخَلْقِهِنَّ بِقَادِرٍ عَلَى أَن يُحْىِ الْمَوْتَى بَلَى إِنَّهُ عَلَى كُلِّ شَىْءٍ قَدِيرٌ
Do they not see that Allah, Who created the heavens and the earth, and was not wearied by their creation, is able to give life to the dead? Yes, He surely is Able to do all things. (46:33)
and,
لَخَلْقُ السَّمَـوَتِ وَالاٌّرْضِ أَكْـبَرُ مِنْ خَلْقِ النَّاسِ
The creation of the heavens and the earth is indeed greater than the creation of mankind. (40:57)
and,
أَءَنتُمْ أَشَدُّ خَلْقاً أَمِ السَّمَأءُ بَنَـهَا
Are you more difficult to create or is the heaven that He constructed? (79:27)
Allah the Exalted and Most Honored said,