Oil used for Lamps
Source: TTT
Exodus 25:6
olive oil for the light; spices for the anointing oil and for the fragrant incense;
Exodus 27:20
And you are to command the Israelites to bring you pure oil of pressed olives for the light, to keep the lamps burning continually.
Matthew 25:3
The foolish ones took their lamps but did not take along any extra oil.