The centurion did not want Jesus to come under his roof because he did not want Jesus to become unclean by entering a Gentile’s house (see Acts 10:28, John 18:28, Acts 11:3, Galatians 2:12). Since Jesus commended his great faith (Matthew 8:10), the centurion must also have felt his personal unworthiness to have Jesus visit him, despite the centurion’s high social status and the Jewish elders’ praise for him (Luke 7:4; see Proverbs 27:2).
By entering the home of the Gentile centurion, Jesus would be considered unclean by the Jewish rabbis (see Acts 10:28, John 18:28, Acts 11:3, Galatians 2:12). The centurion was aware of this and was therefore unwilling to request this of him. His humility also needs to be understood in light of the fact that he was a Gentile approaching Jesus who was a Jew. He undoubtedly felt personally unworthy. It is also important to note the character of this man who is described by Jesus himself as having great faith (Matthew 8:10). What is noteworthy is that this man, who ranked high on the social ladder, considers himself unworthy in the presence of Jesus. This, despite the Jewish elders who spoke on his behalf even expressly noting that he is worthy of being helped (Luke 7:4, see also Proverbs 27:2).1
8 But the centurion replied, “Lord, I am not worthy to have you come under my roof, but only say the word, and my servant will be healed.