This is the seventh month of the Hebrew calendar. The twenty-first day is near the middle of October on Western calendars. (See: [[rc://en/ta/man/jit/translate-hebrewmonths]] and [[rc://en/ta/man/jit/translate-ordinal]])
This idiom is used to introduce a special message from God. See how you translated this in [Haggai 1:1](../01/01.md). Alternate translation: "Yahweh gave a message" or "Yawheh spoke this message" (See: [[rc://en/ta/man/jit/figs-idiom]])
Here the word "hand" refers to Haggai himself. Yahweh used Haggai as the agent to deliver his command. See how you translated this in [Haggai 1:1](../01/01.md). Alternate translation: "through Haggai" (See: [[rc://en/ta/man/jit/figs-synecdoche]])