“I once asked abu ‘Abd Allah (a.s.), about the case of ‘The white twine from the black twine.’ He (the Imam) said, ‘It is the whiteness of the day out of the blackness of the night.’ He (the Imam) said, ‘Bilal and ibn ‘Umm Maktum would say Adhan for the Holy prophet. Ibn ‘Umm Maktum was blind and would say Adhan in the night. Bilal, however, would say Adhan when it was dawn. The Holy prophet said, ‘When you hear the voice of Bilal then stop eating and drinking, because you are in the morning.’”