It was narrated that Jabir bin Samurah said:"Bilal did not delay the Adhan from its proper time, but he sometimes delayed the Iqamah a little
Hadith No. 713
Sunan Ibn Majah
Gradings:
Al-Albani:
Hasan
Muhammad Fouad Abd al-Baqi:
Hasan
Shuaib Al Arnaut:
Daif
Zubair Ali Zai:
Daif