Concerning a man calling the azan for the Fajr prayer and at other times, what is the excellence of the azan and taking great care of the Fajr prayer, as he comes to the masjid about an hour before it?

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

The azan is an act of worship entailing great reward with Allah, the Exalted, since it is the source of notifying and calling the people to attend the prayer, which is the second pillar of Islam after the two testimonies of faith (testifying that there is nothing deserves to be worshipped except Allah and that Muhammad is His Messenger).

There are many authentic Prophetic Ahadeeth on the excellence of the azan. Al-Bukhari and Muslim narrated that the Messenger of Allah, sallallaahu ‘alayhi wa sallam, said:

If only the people knew what it meant to make the call and to be in the first row, then even if they had to draw lots, they would draw lots. If only they knew what it meant to come early (to the prayer), then they would race each other to it. If only they knew what it meant to pray Al-‘Atamah (the night prayer, the ‘Isha’) and Al-Fajr (the dawn prayer), then they would go to them even if crawling.

In Saheeh Al-Bukhari and elsewhere, it is narrated that the Messenger of Allah, sallallaahu ‘alayhi wa sallam, said to Abu Sa‘eed Al-Khudri:

I see that you love sheep and the wilderness. So if you are with your sheep or in the wilderness and call the azan for prayer, then raise your voice with the call. Verily, any of the jinn or humans or anything else that hears the voice of the muezzin will bear witness to it on the Day of Resurrection.

Abu Sa‘eed said, "I heard this from the Messenger of Allah, sallallaahu ‘alayhi wa sallam."

In Saheeh Muslim and elsewhere, it is narrated that the Messenger of Allah, sallallaahu ‘alayhi wa sallam, said, "The muezzins will have the longest necks on the Day of Resurrection."

Imam An-Nawawi said in his commentary on Saheeh Muslim:

"It has been said that this means that they are the people with the highest expectations of the mercy of Allah, the Exalted, because the one who expects something will extend his neck to see what he expects. Thus, this refers to the abundant reward that they will see."

As for taking great care to adhere to the morning prayer, specifically in congregation, there is the Hadeeth in which the Prophet, sallallaahu ‘alayhi wa sallam, said, "Whoever prays ‘Isha’ in congregation, it is as if he stood (in prayer) for half the night; and whoever prays the morning prayer in congregation, it is as if he stood (in prayer) the entire night."

In Saheeh Muslim, it is narrated that he, sallallaahu ‘alayhi wa sallam, said, "Whoever prays the morning prayer is in the protection of Allah, so do not fall short with regard to the rights of Allah, for anyone who does that, Allah will seize him and will throw him face-down into the fire of Hell."

Constantly attending those prayer is evidence of being clear of hypocrisy. In Saheeh Al-Bukhari and elsewhere, it is narrated that he, sallallaahu ‘alayhi wa sallam, said:

There is no prayer heavier on the hypocrites than Al-Fajr and Al-‘Isha’. If only they knew what they meant, they would come to them crawling. I considered ordering the muezzin to announce the iqamah and then order a man to lead the people in prayer while I take a torch to burn the houses of those who did not yet come out for prayer.

Allah knows best.