When and how should one kiss his thumbs during Adhan and what does one recite when doing so?
When the Mu’adhin (Caller to Prayer) recites the first time ‘Ash-hadu anna Muhammad-ar-Rasoolullah’ one should reply as: salala hu alaika ya RasoolAllah. The second time ‘Ash-hadu anna Muhammad-ar-Rasoolullah’ is recited the listeners should reply by saying ‘kuratu ainy bika ya RasoolAollah’.
Both times the nails of the two thumbs should be kissed and touched with the eyes, in the end one should recite ‘Allah huma mut’ani bi sam’i wal basar’, which means, O’Allah protect my hearing and my eyesight.
And Allah ﷻ knows the best
Imam Ahmad Rida Khan رحمة الله تعالى عليه
Translation by Dr Musharraf Hussain Al-Azhari Translator of Majestic Quran, www.majesticquran.co.uk