Jesus, chooses common everyday images familiar to His followers to get close to the kingdom of heaven. The images contain hidden meanings. Imagine the field as the world and the wheat as the good bestowed by God. The darnel is the evil in the world and the enemy works only in darkness to sow the seeds of confusion and discord.
"... when you weed out the darnel you might pull the wheat with it." (Matt 13:29). Darnel is a toxic weed and indistinguishable from wheat. To eradicate the former in an untimely manner would destroy the latter. The parable is instructive on two fronts.
Firstly, it tells us that evil does not originate from God, but is a corruption of the good. The inclination to do evil lies in every human heart as the result of our fallen nature. Only He can separate those who do good or evil when He comes in final judgment (Matt 25:31-45).
Secondly, the impatience of the servants is contrasted with the patience and mercy of the Sower who gazes into our hearts and sees the seeds of goodness; that even within hearts overwhelmed by evil, a modicum of good is retained. He allows good and evil to co-exist, recognising that every saint has a past, and every sinner a future. He makes no rash judgment. He is slow to anger, abounding in love and mercy. (Ps 86:15). In what ways can we imitate Him?
Lord, grant me the wisdom to temper justice with love and mercy.