What is the ruling on raising the finger behind the Imam during verses of mercy and punishment, while saying "Subhanak" and raising the index finger, and is this comparable to raising the finger during the Tashahhud?

What is required when hearing the Qur’an in prayer is to listen attentively and reflect. Raising the finger during recitation is not legislated, because it was not mentioned in the Sharia (definition), and it is a corrupt analogy to the Tashahhud (definition). As for the congregant saying "Subhanak" or other forms of remembrance, it is not legislated unless the Imam pauses, because listening to the recitation is more important. It is permissible for the worshipper—whether Imam, solitary, or congregant—to ask Allah for Paradise and seek refuge in Him from Hell if they pass by a verse that reminds them of it, provided that this does not distract the congregant from the enjoined attentive listening.