Fajr (Dawn) Prayer
How many Adhans (Call of Prayer) are there for Fajr (Dawn) Prayer?
Ibn Mas`ud narrated that the Messenger of Allah (peace be upon him) said, “The (call for prayer) Adhan of Bilal should not stop anyone of you from taking his Suhur for he pronounces the Adhan in order that whoever among you is praying the night prayer, may return (to eat his Suhur) and whoever among you is sleeping, may get up, for it is not yet dawn (when it is like this).” (Al-Bukhari)
In another hadith, the Prophet (peace be upon him) said, “Bilal calls the Adhan during the night, so eat and drink until Ibn Umm Maktum calls (the Adhan)” (Agreed Upon)
Based on the above hadiths, there were two adhans (call of Prayer) at the time of the Prophet (peace be upon him). The first one was for awaking people from sleep or for those who had the intention to fast the next day to have suhur. The next one is offered at the actual time of the Fajr Prayer.
To get more information about the rulings and number of the Adhan of Fajr prayer, you can watch this short video with Dr. Muhammad Salah.
Source: Huda Youtube Channel.