Commentaries:
Robertson's Word Pictures (NT)
The Lord (o kuriov). It is not clear how the word would be understood here by those who heard the message though it is plain that Jesus applies it to himself. The word is from kurov, power or authority. In the LXX it is common in a variety of uses which appear in the N.T. as master of the slave (Matthew 10:24), of the harvest (Matthew 9:38), of the vineyard (Matthew 20:8), of the emperor (Acts 13:27), of God (Matthew 11:20; Matthew 11:25), and often of Jesus as the Messiah (Acts 10:36). Note Matthew 8:25. This is the only time in Matthew where the words o kuriov are applied to Jesus except the doubtful passage in Matthew 28:6. A similar usage is shown by Moulton and Milligan's Vocabulary and Deissmann's Light from the Ancient East. Particularly in Egypt it was applied to "the Lord Serapis" and Ptolemy and Cleopatra are called "the lords, the most great gods" (oi kurioi qeoi megistoi). Even Herod the Great and Herod Agrippa I are addressed as "Lord King." In the west the Roman emperors are not so termed till the time of Domitian. But the Christians boldly claimed the word for Christ as Jesus is here represented as using it with reference to himself. It seems as if already the disciples were calling Jesus "Lord" and that he accepted the appellative and used it as here.
Other Robertson's Word Pictures (NT) entries containing Matthew 21:3:
Mark 11:3
Luke 2:11
Luke 19:33
John 12:14
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