Raising the forefinger when saying Laa ilaaha ill-Allaah after prayer

Saying Subhaan-Allaah,
al-hamdu Lillaah, Allaahu akbar and Laa ilaaha ill-Allaah following the
prayer is a Sunnah that is proven from the Prophet (peace and blessings
of Allaah be upon him) in word and in deed, and there is a great deal of
reward in that. Among the reports that speak of that is the report narrated
by Muslim (597) from Abu Hurayrah, that the Messenger of Allaah (peace
and blessings of Allaah be upon him) said: Whoever glorifies Allaah
thirty-three times after every prayer, and praises Allaah thirty-three
times, and magnifies Allaah thirty-three times, making ninety-nine, and
completes it by saying, ‘There is no god but Allaah alone, with no partner
or associate; His is the Dominion, to Him be praise, and He is Able to do
all things,’ his sins will be forgiven even if they are like the foam of the
sea.” 

As for raising the
forefinger when saying Laa ilaaha ill-Allaah at this point,, we could not
find anything to indicate that it is proven to be Sunnah. 

And Allaah knows best.