Question
When changing the car oil, the station owner keeps the old oil and takes it without an agreement between the two parties. Is it necessary to have a contract between them to be able to take the old oil, or is customary practice governing the matter?
Answer
I say, and with God's success: The owner's leaving the oil for the shopkeeper makes it permissible for the shopkeeper, so the shopkeeper becomes its owner, and he may dispose of it as he wishes. Custom is considered in this matter, and there is no need for an agreement. And God knows best.