Answered by Shaykh Amjad Rasheed
During prayer, I raise my index finger when I say, “illa-llah” in the tashahhud. When should I lower my index finger? Should I keep it raised until the salam? Should I keep it raised during the salam?

In the Name of Allah, Most Merciful and Compassionate
A. What Shaykh Ibn Hajar explicitly states in the Tuhfa (2.80) is that one should not lower it until the end of the tashahhud. The immediately apparent meaning of this, as Shabramallisi states, is that one should lower it after completing the tashahhud and before beginning the first salam.
Ramli in his Nihaya and Ibn Hajar in his Sharh Ba Fadl say that one should not lower it until the salam. Shabramallisi comments, “It is possible to reconcile what the commentator, Muhammad al-Ramli, says with what Ibn Hajar said [i.e. in the Tuhfa] by interpreting until to mean after, which corresponds to the dominant opinion.”
The Upshot
The upshot is that one should lower it after completing the tashahhud and before starting the first salam. The immediately apparent meaning of Shabramallisi’s comment, “… one should lower it before the salam,” indicates that one should recite the tashahhud along with [h: the blessings on the prophet and] the following du’a and not lower [h: the finger] — if one so desires — until just before the salam.
Amjad Rasheed
Amman, Jordan
(Translated by Hamza Karamali)