ENOfficial
Ibn ‘Umar reported God’s Messenger as saying, “Two characteristics are suspended on the necks of those who call the adhan for the Muslims, their fasting and their prayer.” Ibn Majah transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنِ ابْنِ عُمَرَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: " خَصْلَتَانِ مُعَلَّقَتَانِ فِي أَعْنَاقِ الْمُؤَذِّنِينَ لِلْمُسْلِمِينَ: صِيَامُهُمْ وَصَلَاتُهُمْ ". رَوَاهُ ابْنُ مَاجَه
sunnah.com