Abd al-Aziz bin Rufay' (may Allah have mercy on him) said: I saw Sayyiduna Abu Mahdhurah (may Allah be pleased with him) come when someone had already given the adhan before him; then he gave the adhan and the iqamah.
The chain of this report is sahih (authentic), and it corroborates what has preceded.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 1871