Shaikh At-Tah?w? held and supported this opinion and reported in his “Sharh” the same opinion from Ab? Han?fah, Ab? Y?suf and Muhammad ... (1)

To conclude, reciting Tathw?b in the second Fajr ’Ath?n is Bid‘ah, the matter is even worse when the first ’Ath?n is abandoned. Those who do so have indeed fell in All?h’s ( - عز وجل -) reproach: [ أتستبدلون الذي هو أدنى بالذي هو خير]

‘ Would you exchange that which is better for that which is lower?’ (2)

and [ لو كانوا يعلمون]

‘ If they but knew [the gravity of their sin]’. (3)

[8/ 23] It is worth mentioning here that one of the widely abandoned of the Sunnan regarding ’Ath?n is appointing two Mu’aththins [for the same mosque]; one calls the first Fajr ’Ath?n and the other calls the second. This is an affirmed Sunnah which is established in many authentic ah?d?th. May All?h bless him who revives this Sunnah. (4)

the following paragraphs discuss some mistakes people do when hearing the ’Ath?n:

[9/ 23] Wiping one’s eyes- while the ’Ath?n is being recited with one’s thumbs:

In his “M?jib?t Ar-Rahmah Wa ‘Az?’im Al-Magfirah”, Abul ‘Abb?s Ahmad Ibn Ab? Bakr Ar-Radd?d Al-Yam?n? -a sufist- related through a chain of narrators full of unknown narrators besides being a disconnected one, from Al-Khadir to have said: ‘whoever says: “Welcome my beloved one Muhammad Ibn Abdill?h”, then kisses his two thumbs and then wipes his eyes with them when the Mu’aththin says, “Ashhadu Anna Muhammadan Ras?lull?h”, will never suffer of ophthalmia’.