10:3 the porter. In the symbology, the porter probably represents John the Baptist, who prepared the way for the Shepherd—both sheep and Shepherd being symbolically admitted into God’s new covenant relationship by baptism. Thereafter, however, Jesus Himself led His sheep, both in and out.
10:6 parable. This word is usually translated as “proverb.” John never uses the standard word for “parable,” which is used fifty times elsewhere.
10:7 I am the door. Jesus here claims to be the actual “door” of the sheepfold. This is the third of the great “I am’s” of John’s gospel (also John 10:9).
10:8 thieves and robbers. Any other teachers or leaders (in the immediate context, the scribes and Pharisees, but in the broader context, any other false leaders) who profess to lead people to God are, spiritually speaking, like robbers, who would steal souls away from true saving faith, which is only to be found in Christ.
10:9 go in and out. The Lord Jesus would lead His sheep out of the small fold of the Old Testament (or “old covenant”) into the broader fold of the new covenant, centered on His church instead of on a chosen nation. In another sense, He would lead His sheep “in” for fellowship, rest and training, then “out” for service.
10:11 good shepherd. This is the fourth of the Lord’s “I am” claims in the Gospel of John. This also is another shadow of His coming substitutionary death—not only guiding His sheep, but also dying for them.
10:14 the good shepherd. The Greek word for “shepherd” is the same as for “pastor.” Thus Jesus was—and is—the good pastor. By extension today, a good pastor is one who leads his flock into good pasture, who knows his flock, is known by his flock, and would even give his life for his flock. Note I Peter 5:2-5 and Hebrews 13:20,21.
10:16 other sheep I have. The “other sheep” of which the Lord spoke were obviously not of the “fold” of Israel. They were Gentiles who, through His work, would soon be brought into the same fold (compare Ephesians 2:11-22).