This is a question based on fatwa no.81988.If both moving the finger & not moving are correct,can I do the both in my prayers(Except Fajr). For example,in Asr prayer,I keep my finger straight in the 2nd rakha & moving in the 4th rakha.By this Iam following both the sunnah.I feel Iam not deviating from the sunnah.If I can't then pls tell me which of the 2 will be the best to follow.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

As explained in the mentioned Fatwa, both acts are permissible, however, it is better to move the finger sometimes and to leave moving it other times. Doing both acts in the same prayer is permissible, and not obligatory, and you may also do one of the two acts in a prayer and the other in another prayer, but without always abiding by the order you mentioned in your question, i.e. one act for the first Tashahhud and another for the last Tashahhud.

Allaah Knows best.