Honor ___ father ...

THY

This two-letter word appears in the Lord’s Prayer and is an old-fashioned way to say "your," often used in solemn or biblical contexts.

This clue references the well-known biblical commandment "Honor thy father and thy mother" from the King James Version of the Bible. The missing word is "thy," an old English term meaning "your," which fits both the phrasing of the original text and the crossword’s space constraints. It’s a direct quote, so no wordplay is involved—just a test of familiarity with classic religious language.