Imam Muhammad Amin Ibn Abidin, agreed upon as the leading reference for fatwa in the Hanafi school, first mentions the scholars who said that it is recommended to do, and then mentioned that none of the hadiths that mention this from the Messenger of Allah (Allah bless him and give him peace) are authentic.

Ibn Abidin's actual text is as follows, from his Radd al-Muhtar (aka al-Hashiya or al-Shami)

"It is recommended to say, after hearing the first Shahada [in the adhan], Salla Allahu `Alayka Ya Rasul Allah ('May Allah send blessings on you, O Messenger of Allah'), and after the second of them, Qarrat `Ayni Bika Ya Rasul Allah ('May my eyes rejoice with you, O Messenger of Allah').

"Then one should say, Allahumma matti`ni bi's Sam`i wa'l Basar ('O Allah, keep blessing me with hearing and sight'), after placing the nails of both thumbs on one's eyes, for the Messenger of Allah (Allah bless him and give him peace) will be his guide into Janna [if he does] - as mentioned in Kanz al-`Ibad, via al-Quhustani [in his Jami` al-Rumuz].

"This has also been mentioned in al-Fatawa al-Sufiyya. It has been reported in Kitab al-Firdaws that, "Whoever kisses the nails of both thumbs upon hearing Ashhadu anna Muhammda-r Rasul Allah, I shall be his guide and shall enter him in the ranks of Janna."

"The details are in the Hawashi al-Bahr of al-Ramli, from al-Maqasid al-Hasana of al-Sakhawi.

"Al-Jirahi mentioned this, too, and gave a lengthy exposition, then said, "None of these narrations has been authentically established (lam yasihh) from the Messenger of Allah (Allah bless him and give him peace)." [Ibn Abidin, Radd al-Muhtar, 1: 397-8]

The exact Arabic text may be found in the left margin.

The scholars differed, though, whether it is of the weak hadiths that may be used to establish virtuous actions, because excessively weak hadiths cannot be acted upon even for virtuous actions. Many Hanafis (and scholars of other schools) held that they are. Others differed; it is a question of scholarly difference in ijtihad.

The condition for recommended actions established by weak hadiths or the ijtihad of scholars is that one not have the firm conviction that this is established from the Prophet (Allah bless him and give him peace) himself. However, if one does it because the some scholars have mentioned it to be a virtuous or beneficial action, then there is nothing wrong with it. If one is firmly convinced that the Prophet (Allah bless him and give him peace) himself did this or encouraged it, which is not authentically established, then it would be an innovation.

This is a practice that many of the righteous of this Ummah and some of its major scholarly authorities have found to have spiritual benefits, and is also an expression of love for the Prophet (Allah bless him and give him peace), and may be acted upon as a recommended act as such. It is supported by some narrations from Sayyiduna Abu Bakr (Allah be pleased with him), though there is strong difference in their establishment

In short, it is neither something that is a strongly recommended action according to the Shariah nor a baseless innovation. The scholars mention that any time an issue is differed upon among the scholars of the four schools of Sunni Islam, one cannot condemn someone who does something one differs with.

Also, we should not forget that scholarly disagreements are limited to the sphere of scholars, and should not spill over to non-scholars. An example is two pharmacists who spend hours vigorously arguing (and questioning the soundness of each other's judgment) about which of two medications is the one two use, each of them advocating one of them. They get very harsh with each other... but back in the pharmacy, when someone comes with the medicine they were advocating against, or when someone asks, they don't make much of the issue...

May Allah guide us to that which is best.

Faraz Rabbani