لَا يَسْتَكْبِرُونَ عَنْ عِبَادَتِهِ وَلَا يَسْتَحْسِرُونَ
They are not too proud to worship Him, nor do they grow weary. (Al-Anbiyāʾ 21:19)
Arrogance would mean considering oneself above obedience; weariness or exhaustion would describe failing through fatigue or depletion. The verse negates both qualities for angels in their worship.
These claims should not be measured by analogies with human physical exhaustion. Their subject is a class of beings whose mode of worship is known through revelation. The immediate theological point is their unwavering service.