Placing a hand on holy books like the Holy Quran, Torah, or Injeel, etc., while taking an oath is not necessary for the oath to be valid. The oath becomes valid even without placing a hand on these books. However, if this is done to emphasize the oath and to instill fear in the person taking the oath so that they do not swear falsely, then it is permissible. (Al-Fatawa al-Hindiyyah: 2/51,52) (Derived from: Darsi wa Ilmi Aham Masail, p: 314)