Ан-Нахль 16:11

It will be noticed that all verses cited above point out to Divine blessings and mention the creation of the universe with unprecedented wisdom. In them, those who ponder find significant indicators and proofs which lead them to perceive the truth of Tauhid, the truth that Allah Ta` ala is One. Therefore, while these blessings are being mentioned, they are tied up with a notice to pay attention, think, understand and accept advice. Consequently, at the end of verse 11, it was said: إِنَّ فِي ذَٰلِكَ لَآيَةً لِّقَوْمٍ يَتَفَكَّرُ‌ونَ (Indeed, in that, there is a sign for a people who ponder). The reason is that the linkage of pastures, crops, trees and their flowers and fruits with the creativity and wisdom of Allah Ta` ala needs some reflection. If one ponders over a grain or pit, he will come to realize that simply putting it inside the land and watering it cannot automatically cause it to grow into a huge big tree with flowers of many colours opening up all over it. No tiller or farmer or land owner has made this happen. Their role in this process is nil. All this is linked with and tied to the creativity and wisdom of the Absolute Master.

After that, when came the description of the night and day, the sun, the moon and the stars which have been made subservient by His command, it was said in the concluding sentence of verse 12: إِنَّ فِي ذَٰلِكَ لَآيَاتٍ لِّقَوْمٍ يَعْقِلُونَ (Indeed, in that, there are signs for a people who understand). Given here is the hint that these things are of course subservient to the command of Allah, an open fact which does not need a lot of thinking. Anyone having some reason in him would understand, because there was obviously some human input in the growth of vegetation and trees, but, in this case, there is none.