"Have they not seen the birds above them, spreading [their wings]?"—with their wings; meaning: indeed they have seen them. "And they contract [them]"—meaning: when the bird stops while spreading its wings, it does not move; according to the interpretation of some of them.
﴿أَوَلَمْ يَرَوْا إِلَى الطَّيْرِ فَوْقَهُمْ صافات﴾ بِأَجْنِحَتِهَا؛ أَيْ: قَدْ رَأَوْهَا. ﴿وَيَقْبِضْنَ﴾ يَعْنِي: إِذَا وَقَفَ الطَّائِرُ صَافًّا بِجَنَاحَيْهِ لَا يَزُولُ؛ فِي تَفْسِيرِ بَعضهم.