No man, when he has lighted a lamp, covers it with a vessel, or puts it under a bed; but sets it on a lampstand, that they who enter in may see the light.
All Commentaries on Luke 8:16 Go To Luke 8
Eusebius of Caesarea
AD 339
As if He said, As a lantern is lighted that it should give light, not that it should be covered under a bushel or a bed, so also the secrets of the kingdom of heaven when uttered in parables, although hid from those who are strangers to the faith, will not however to all men appear obscure. Hence he adds, For nothing is secret that shall not be made manifest, neither any thing hid that shall not be known, and come abroad. As if He said, Though many things are spoken in parables, that seeing they might not see, and hearing they might not understand, because of their unbelief, yet the whole matter shall be revealed.