Dinaiy (the Dinaites) appears in Ezra 4:9 as one of the groups that wrote to King Artaxerxes to oppose the rebuilding of Jerusalem's walls. These were peoples transplanted into the former Northern Kingdom by Assyria, the syncretic population that became known as the Samaritans. Their opposition to the returning Jewish exiles was both political and religious.
The opposition of the Dinaites and their compatriots represents a recurring biblical pattern: when God's people seek to rebuild what was destroyed, resistance arises. Nehemiah faces this; the early church faces it (Acts 4-5); missionaries face it today. The strategy of the adversary is to discourage, intimidate, and use official channels to halt God's work. Yet Jerusalem's walls went up despite every letter and opposition — because 'the people had a mind to work' (Nehemiah 4:6) and their God was greater than their opponents.