within about fifteen minutes as stated in Ibn ‘Umar’s ( - رضي الله عنه -) had?th who said: ‘“As-Sal?tu Khairun Minan Nawm”, used to be recited in the first Fajr ’Ath?n twice after reciting “Hayya ‘Alal Fal?h”’. (1) There is also Ab? Mahth?rah’s had?th, although it is a general one that encompasses both the first and the second ’Ath?ns. However, another narration for the same had?th specifies its generality, it states: ‘[The prophet ( - صلى الله عليه وسلم -) said:] when you call the first Fajr ’Ath?n, say: “As-Sal?tu Khairun Minan Nawm, As-Sal?tu Khairun Minan Nawm”’. (2) The two hadiths are then compatible.

Commenting on the second had?th, As-San‘?n? said: ‘This had?th specifies the generality of the other narrations. Ibn Raslan reported that Ibn Khuzaimah considered it authentic and stated that ‘Thathw?b should be recited in the first Fajr ’Ath?n which is dedicated for waking people up while the second ’Ath?n is for pronouncing that Fajr time is due and people should attend the Sal?t’.

This was adopted from “Takhr?j Az-Zarkash? Li ’Ah?d?th Ar-R?fi‘?” and the same point is mentioned in “As-Sunnan Al-Kubr?” by Al-Baihaq? that Ab? Mahth?rah said that Tathw?b used to be recited in the first Fajr ’Ath?n complying with the prophet’s ( - صلى الله عليه وسلم -) order.

Accordingly, I believe that the phrase “As-Sal?tu Khairun Minan Nawm” is not part of the ’Ath?n which calls people to attend the congregational Sal?t when its time is due, instead it is part of the first ’Ath?n that is called to wake people up; which -unfortunately- was substituted with Tasb?h’. (3)