وعليكم السلام ورحمة الله وبركاته The Sunnah with regards to pointing with the index finger is to point with it during the time of supplication (Dua) and this includes the entire words of the Tashahhud according to the correct opinion . Therefore both sayings are among the sayings of the people of knowledge, so either you put down the index finger before the Tasleem or after it . It is all same even though it is better to put it after the Tasleem , because the Tasleem is a form of Dua as well... and all of that is good In Sha Allah .