Hadith.872 - Abu Basir narrated from one of the Imams (as) that He said:
"Bilal was a righteous servant who said
'I will not call the adhan for anyone after the Messenger of Allah (sw).'
Therefore, on that day, 'Hayya 'ala khayr al-'Amal' (Hasten to the best of deeds) was left out."