It is narrated from Sayyiduna Bilal (may Allah be pleased with him) that he used to say 'Hayya 'ala khayr al-'amal' (Come to the best of deeds) in the morning adhan, so the Prophet (peace and blessings be upon him) ordered him: "Say 'As-salatu khayrun min an-nawm' (Prayer is better than sleep) in its place." So he gave up saying 'Hayya 'ala khayr al-'amal'.
This wording is not established from the Prophet (peace and blessings be upon him) in what he taught Bilal and Abu Mahdhurah, and we dislike adding it (to the adhan); and success comes from Allah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 1994
Hadith Gradingمحدثین:ضعيف جدًا
Hadith Takhrij«ضعيف جدًا۔ أخرجه الطبراني في الكبير 1071»