In these verses shade is one of the rewards of Paradise, deep, lasting and extended, where the believers recline with their spouses. Its lengthening, made visible by the sun, is a sign of Allah, and shadows themselves prostrate to Him morning and evening. The verses also mention the clouds that shaded those given manna and quails, and the shade to which Moses withdrew to call on his Lord.
Verses gathered from a topical index of the Quran, in Mushaf order; every verse is quoted in full.
Have you not considered your Lord - how He extends the shadow, and if He willed, He could have made it stationary? Then We made the sun for it an indication.