Again, the kingdom of heaven is like unto treasure hid in a
field; the which when a man hath found, he hideth, and for joy thereof
goeth and selleth all that he hath, and buyeth that field.
Again, the kingdom of heaven is like unto a merchant man, seeking
goodly pearls: Who, when he had found one pearl of great
price, went and sold all that he had, and bought it.
Again, the kingdom of heaven is like unto a net, that was cast into the
sea, and gathered of every kind: Which, when it was full,
they drew to shore, and sat down, and gathered the good into vessels,
but cast the bad away. So shall it be at the end of the
world: the angels shall come forth, and sever the wicked from among the
just, And shall cast them into the furnace of fire: there
shall be wailing and gnashing of teeth. Jesus saith unto
them, Have ye understood all these things? They say unto him, Yea,
Lord. Then said he unto them, Therefore every scribe
which is instructed unto the kingdom of heaven is like unto a man that
is an householder, which bringeth forth out of his treasure things new
and old. And it came to pass, that when Jesus had
finished these parables, he departed thence. And when he
was come into his own country, he taught them in their synagogue,
insomuch that they were astonished, and said, Whence hath this man this
wisdom, and these mighty works?
St. Gregory the Great in his Parables of the Gospel, Homily XI said:
"The Kingdom of Heaven, dearly beloved brethren, is compared to earthly thing, so that our soul may rise to the unknown from that with which it is familiar: so that our love for what we know may kindle and inflame our desires for what we do not know as yet…We should not that the treasure, once found, is hidden in order to preserve it, because the desire of celestial happiness is not sufficient shield against the evil spirits for him who does not hide it from human flattery. In this present life we are, as it were, in progress along a way which leads to our native land. As we go on our way, the malignant enemies, like robbers, attack us…I say this not that our neighbor should not see our works, as it is written, 'That they may see your good works and glorify your Father who is in heaven,' (Mt.5:16), but so that we should not seek praise for what we do before others…The treasure stands for heavenly desires and the field in which this treasure is hidden signifies the conduct by which we achieve them…Like a merchant in quest of good pearls…he who attains a perfect knowledge of the heavenly life as far as this is possible, is supremely happy to relinquish all he loved before…Of this love Solomon says, 'Love is strong as death,' because, as death strips the body of life, so love of life eternal kills the love of temporal things…Holy Church is compared to a fishing net, because she also is entrusted to fishermen and by means of her we are drawn out of the waves of this world and brought to the heavenly kingdom lest we be swallowed up in the abyss of everlasting death…At present we mingle good and bad together, like the fishes in the net, but the shore will tell what was in the net."
Origen in his De Principils Book IV said:
"…'the kingdom of heaven is like a treasure hid in a field; which when a man finds, he hides it, and for joy thereof goes away and sells all that he has, and buys that field.' By which similitude, consider whether it be not pointed out that the very soil and surface, so to speak, of Scripture–that is, the literal meaning–is the field, filled with plants and flowers of all kinds; while that deeper and profounder 'spiritual' meaning are the very hidden treasures of wisdom and knowledge which the Holy Spirit by Isaiah calls the dark and invisible and hidden treasures, for the finding out of which the divine help is required: for God alone can burst the brazen gates by which they are enclosed and concealed, and break in pieces the iron bolts and levers by which access is prevented to all those things which are written and concealed in Genesis respecting the different kinds of souls, and of those seeds and generations which either have a close connection with Israel or are widely separated from his descendants; as well as what is that descent of seventy souls into Egypt, which seventy souls became in that land as the stars of heaven in multitude. But as not all of them were the light of the world – 'for all who are of Israel are not Israel' – they grow from being seventy souls to be an important people, and as the 'sand by the sea-shore innumerable.'"
Aphrahat (an Assyrian author of the fourth century from Persia) in his Demonstration 6 (Of Monks) wrote a beautiful piece of inspiration using the exhortation "Let us…" time and time again, encouraging his listeners by scripture to live lives that are intentional and honorable to the Father. (Full text here…wonderful reading, very inspiring and a good summary of Christ's teachings, as well.) I'll just copy a small part from Demonstration 6 regarding the treasure hidden in the field (and including a reference to yesterday's gospel reading about the wheat and the tares).
"Let us hunger for righteousness, that we may be satisfied (Matt5:6) from the table of His Kingdom. Let us be the salt of truth, that we may not become food for the serpent. Let us purge our seed from thorns, that we may produce fruit a hundred-fold. Let us found our building on the rock (Matt7:24) that it may not be shaken by the winds and waves. Let us be vessels unto honour (II Tim.2:21) that we may be required by the Lord for His use. Let us sell all our possessions, and buy for ourselves the pearl, (Matt13:46) that we may be rich. Let us lay up our treasures in heaven (Matt6:20) that when we come we may open them and have pleasure in them. Let us visit our Lord in the persons of the sick, (Matt25:33-35) that He may invite us to stand at His right hand. Let us hate ourselves and love Christ, as He loved us and gave Himself up for our sakes. Let us honour the spirit of Christ, that we may receive grace from Him. Let us be strangers to the world (Jn17:14) even as Christ was not of it. Let us be humble and mild, that we may inherit the land of life…Let us be partakers in His suffering, that so we may also rise up in His resurrection."