`Adi bin Hatim:
When the above verses were revealed: 'Until the white thread appears to you, distinct from the black
thread,' I took two (hair) strings, one black and the other white, and kept them under my pillow and
went on looking at them throughout the night but could not make anything out of it. So, the next
morning I went to Allah's Messenger (ﷺ) and told him the whole story. He explained to me, "That verse
means the darkness of the night and the whiteness of the dawn."