Hawzah News Agency – The commander of the faithful, Imam Ali peace be upon him says:

الخَوفُ سِجْنُ النّفْسِ عَن الذُّنوبِ، ورادِعُها عنِ المَعاصي.

'Fear is the soul's prison [preventing it] from sinning and is its deterrent from disobedience.'

Source: Ghurar al-Hikam, no. 1987