This phrase was first introduced into the adhan by the Prophet (sawa) at Ghadir Khumm. Ghadir Khumm is a place outside of Makkah where the Prophet (sawa) told everybody to stop after returning from Hajj during the last year of his life. When they stopped, he called all the Muslims together and ordered Bilal (ra) to call the adhan. When Bilal reached “hayya ‘alal falah” the Prophet (sawa) stopped him and said to repeat “hayya ‘ala khayril ‘amal” two times. This phrase means: Make haste towards the best of deeds. The deed he was speaking of holds great importance and upon completing it the religion was perfected. This deed was the appointment of Ali (as) as his successor.
After the Prophet’s (sawa) martyrdom, Abu Bakr seized power while leaving the Prophet (sawa) unburied for three days, in spite of the Prophet’s (sawa) appointment of Ali as the khalif (successor)! Abu Bakr and Umar conspired while the Ahl-ul-Bayt (as) were preparing the funeral rites. This is where the split came about in the community. Some sided with Ali (as) following the Prophet’s (sawa) instructions. These people were (and are) called the Shia (“Shi’a” meaning follower, and the term here specifically referring to “followers of Ali”). Some sided with the usurper of khalifat Abu Bakr. These followers of Abu Bakr and ‘Umar are called the Sunni sect.
Bilal (ra) sided with Ali (as) and thus as a form of protest quit calling the adhan to show people how serious this was! Abu Bakr got very angry and upset with Bilal (ra) and exiled him to Syria. He later died and was buried there. He was replaced by someone else and that person was told not to recite the phrase Hayya ‘ala khayril ‘amal. The unjust rulers were afraid that if it were recited the people would remember the rightful claim of Ali (as) and realize the falsity of Abu Bakr’s rule.
As followers of the Prophet (sawa) we acknowledge Ali’s (as) right and recognize him as the first Imam. Knowing this, we call the adhan with the phrase Hayya ‘ala khayril ‘amal as the Prophet (sawa) ordered it.
Excerpt from Mystery of the Shia by Mateen J. Charbonneau Available at: