The field is the world (verse 38). The treasure is a symbol of the members of the church. In the Old Testament, God calls Israel His "special treasure" (Exodus 19:5; Psalm 135:4) and "My jewels" (Malachi 3:16-17, margin: "special treasure"). In the New Testament, the apostle Peter states that the elect are God's "own special people" (I Peter 2:9-10). This title was transferred from ancient Israel to spiritual Israel, the church (Galatians 6:16). Since Israel is biblically a type of the New Testament church, the "treasure" in this parable represents the church.
The man hides his treasure in the world. "Hid" is used in a negative sense in the Parable of the Leaven, but the context of the Parable of the Hidden Treasure is positive. Prior to their calling, the individual members of the church are lost, but then they are found (called by God) and hidden again in the world (Ephesians 2:1-7). We were once hidden in the world by default because we were just like the world, but we were not hidden from God. He knew who we were before we were called (Psalm 71:5-6; Isaiah 49:1; Jeremiah 1:5; Luke 1:76; Romans 8:28-29; Galatians 1:15-16; II Timothy 2:19-21).
The man is Christ. Jesus reveals here how He views the world in relation to the church. Instead of glorifying us immediately, He hides us after we are called (John 17:11, 14-18) by physically sending us back into the world. The world camouflages us because we still physically look like the world, but being regenerated members of God's church, we are radically different spiritually. We are set apart or sanctified by God's truth (John 17:17), and the world does not readily notice that we have His truth in our hearts and minds. No longer are we hidden in the world because we conform to it, but for the opposite reason. We are hidden in the world with Christ (Colossians 3:3), and the world recognizes neither Him nor us (see John 1:10).
Jesus gave His all, the ultimate sacrifice—His own blood—His life—for us (John 3:16-17; Acts 20:28). His attitude of joy in doing so shows the genuineness of His self-sacrifice for His treasure (Hebrews 12:2). Even though He had to endure crucifixion, He was elated to redeem or purchase His church—those who would become His bride (Revelation 19:7). Christ reflects His Father in every way, and God is a God of joy. When we receive His Spirit, we also begin to receive His joyous nature as a fruit of the spirit (Galatians 5:22). When we use God's Spirit, joy is produced. As God's elect, we have Christ dwelling in us, and by doing the will of the Father as He did, we can have His joy.
Christ now sits at the right hand of God, continually appearing in the Father's presence, making intercession for us as our Mediator (Romans 8:34; Hebrews 4:14-16; 9:24). Jesus receives great joy from knowing that He is presently in the process of saving the firstfruits of God's Kingdom and will later do the same for the rest of humanity. He maintains His joyous excitement by looking forward to the glorious future of the Family of God and by always doing the will of the Father.
Jesus Christ our Savior found us, a special treasure in the world, and gave His all to call us out of the world and redeem us. He now owns us, and through sanctification, He protects us and hides us from the world.