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.
Or else the Lord warns His disciples to be as light, in their life and conversation; as if He said, As a candle is put so as to give light, so all will look to your life. Therefore be diligent to lead a good life; sit not in corners, but be ye a candle. For a candle gives light, not when placed under a bed, but on a candlestick; this light indeed must be placed on a candlestick, that is, on the eminence of a godly life, that it may be able to give light to others. Not under a bushel, that is, in things pertaining to the palate, nor under a bed, that is, in idleness. For no one who seeks after the delights of his palate and loves rest can be a light shining over all.