Church Fathers on Mark 4:21

Or else the candle is the discourse concerning the three sorts of seed. The bushel or the bed is the hearing of the disobedient. The Apostles are the candlestick, whom the word of the Lord hath enlightened.

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…

Or, because the time of our life is contained under a certain measurement of Divine Providence, it is rightly compared to a bushel. But the bed of the soul is the body, in which it dwells and reposes for a time. He therefore who hides the word of God under the love of this transitory life, and of carnal allurements, covers his candle with a bushel or a bed.