Sahih al-Bukhari Book 10, Hadith 13
Allah's Messenger (ﷺ) said, "If the people knew the reward for pronouncing the Adhan and for standing in
the first row (in congregational prayers) and found no other way to get that except by drawing lots
they would draw lots, and if they knew the reward of the Zuhr prayer (in the early moments of its
stated time) they would race for it (go early) and if they knew the reward of `Isha' and Fajr (morning)
prayers in congregation, they would come to offer them even if they had to crawl."
Allah's Messenger (ﷺ) said, "Whoever after listening to the Adhan says, 'Allahumma Rabba hadhihi-dda` watit-tammah, was-salatil qa'imah, ati Muhammadan al-wasilata wal-fadilah, wa b`ath-hu maqaman mahmudan-il-ladhi wa`adtahu' [O Allah! Lord of this perfect call (perfect by not ascribing partners to You) and of the regular prayer which is going to be established, give Muhammad the right of intercession and illustriousness, and resurrect him to the best and the highest place in Paradise that You promised him (of)], then my intercession for him will be allowed on the Day of Resurrection".
Once on a rainy muddy day, Ibn `Abbas delivered a sermon in our presence and when the Mu'adhdhin pronounced the Adhan and said, "Haiyi `ala-s-sala(t) (come for the prayer)" Ibn `Abbas ordered him to say 'Pray at your homes.' The people began to look at each other (surprisingly). Ibn `Abbas said. "It was done by one who was much better than I (i.e. the Prophet (ﷺ) or his Mu'adh-dhin), and it is a license.'