the messenger of god had a container with kohl in it which he would use as kohl before going to sleep. the messenger of god was heard saying are from manna and their water is a cure for the eyes.
وكانت لرسول الله محكلة فيها إثمد يكتحل منها عند النوم. وسمع رسول الله يقول من المن وماؤها شفاء للعين .