Messenger (may peace be upon him) had two muezzins


Ibn 'Umar,
may Allah be pleased with them, reported: Allah's Messenger (may peace be upon him) had two muezzins (callers to Prayer), Bilal and 'Abdullah bin Umm Maktum, who (the latter) was blind.
Narrator: Abdullah ibn Umar updated: Muslim - Source: Sahih Muslim - or page number: 380
Updated summary of the rule: It is true

...كان لرسول الله صلى الله عليه وسلم مؤذنان : بلال وابن أم مكتوم الأعمى .
الراوي: عبدالله بن عمر المحدث: مسلم - المصدر: صحيح مسلم - الصفحة أو الرقم: 380
خلاصة حكم المحدث: صحيح