are signs for those of understanding.”
[Āl ‘Imrān: 190]

Thus the Most High gave them a sign through the movement of the celestial spheres, in the measure His creatures need for their welfare, whose benefits to them are plain: night, which was appointed for their rest and to cool the excessive heat of the sun upon their crops and fruits; and day, which was appointed for them to go about earning their livelihood, within the limits of what they can bear.

Were it always night for them, its darkness would harm them, keeping them from attending to their welfare and preventing them from securing what benefits them. Likewise, were it always day, that too would harm them: its light, together with their eagerness to earn a livelihood, would prompt them to pursue it beyond what they could endure, until insufficient rest brought about their ruin. He therefore allotted them a portion of daytime for their activities that does not take them beyond their capacity, and a portion of nighttime for their rest that does not fall short of meeting their needs, so that balance might thereby be achieved in