Theophylact of Ohrid
Catena Aurea · Markusevangelium 4
And he said unto them, Is a candle brought to be put under a bushel, or under a bed? and not to be set on a candlestick? For there is nothing hid, which shall not be manifested; neither was any thing kept secret, but that it should come abroad. If any man have ears to hear, let him hear. And he saith unto them, Take heed what ye hear: with what measure ye mete, it shall be measured to you: and unto you that hear shall more be given. For he that hath, to him shall be given: and he that hath not, from him shall be taken even that which he hath.
That is, that none of those things which are said to you by me should escape you. With what measure ye mete, it shall be measured to you, that is, whatsoever degree of application ye bring, in that degree ye will receive profit.