When is the tathwib in the Fajr prayer, in the first adhan or the second adhan?

The questioner : Okay, Shaykh, two of the brothers differed on the issue of the tathwib in the Fajr adhan, whether it is in the first or the second. The first cited as evidence the hadith of the fasting adhan, meaning the hadith: The second cited as evidence the hadith of Ibn Umm Maktum: What is your opinion? Also, regarding the first adhan, is it specific to Ramadan or is it general?

The Shaykh : The tathwib, without a doubt, is in the first adhan, and it is general for all the days of the year. As for the fact that in one hadith Bilal is mentioned in the first adhan, and in another narration Ibn Umm Maktum is mentioned, that is due to a difference in circumstances. Sometimes Bilal’s duty was the first adhan, and the second adhan was for 'Amr ibn Umm Maktum, and sometimes the matter was the opposite: the first adhan for 'Amr and the second adhan for Bilal. This is how the scholars of hadith reconciled the two hadiths. But this difference in who calls the first adhan and who calls the second adhan does not change the reality of the Sunnah, which is that the phrase: is specific to the first adhan; because this is explicit in the hadith of Ibn 'Umar, which al-Nasa'i and others narrated: And likewise in the hadith of Abu Mahdhura. This is established in the first adhan, and there is absolutely no disagreement on that.
The Shaykh : As for the difference in the mu'adhdhin between the first and the second adhan, and vice versa, it does not change anything about the reality of this Sunnah.

The questioner : The second question says: Also, regarding the first adhan, is it specific to Ramadan or is it general?

The Shaykh : I answered it, may Allah bless you. It is general for all the days of the year.