'I Am Not Worthy' in the Bible

I indeed baptize you in water, for repentance; but he that cometh after me is mightier than I, whose sandals I am not worthy to bear; he will baptize you in the Holy Spirit and in fire.

But the centurion answered and said, Lord, I am not worthy that thou shouldst come under my roof; but only command with a word, and my servant will be made well.