And you shall command the children of Israel that they bring you pure oil of pressed olives for the light, to cause the lamp to burn continually (Exodus 27.20)
As a child, I remember always having an olive oil vigil lamp to light up the icons in my room. It was comforting because I didn’t like my bedroom too dark and it seemed like something living was there to comfort me… breathing in the oxygen, giving off heat. Its reflection on the icons of Christ and the Virgin Mary was all I saw in my dark room. I never felt alone when my vigil lamp was lit. I have continued to maintain one as the years have passed.
Since the lamp is an open flame, I am careful where I place it. We have ours on a tall dresser and have mounted the icons on the wall behind it. It can’t be knocked over and it doesn’t heat anything above it to be a fire hazard.