raising finger in tashahhud

Question- when exactly do you raise the finger in tashahud and when do u put it down

Answer- the appropriate time to raise your finger in Tashahudd is when you say “laa” and put it down on illallah. As stated in shami Vol 1 pg. 509
الصحيح أنه يشير بمسبحته وحدها يرفعها عند النفي يضعها عند الإثبات