Commentators explain that this verse outlines a divinely arranged, two-step system for supporting the ministry. First, the people of Israel gave their tithes to the Levites (which included the singers and gatekeepers). Then, the Levites gave a tenth of what they received—the "tithe of the tithe"—to the priests, the sons of Aaron. This ensured all who served in the temple were provided for according to God's command.