Command the children of Israel that they bring thee the purest oil of the olives, and beaten with a pestle: that a lamp may burn always,
In the tabernacle of the testimony without the veil that hangs before the testimony. And Aaron and his sons shall order it, that it may give light before the Lord until the morning. It shall be a perpetual observance throughout their successions among the children of Israel.
St Athanasius b. 296
“Though the deceased is buried in the earth, thou must not omit to burn oil and wax on his grave, for this is pleasing to God and merits great reward.”