This is the name of the first month of the Hebrew calendar. Aviv is during the last part of March and the first part of April on Western calendars. See how you translated this in [Exodus 13:4](../13/04.md). (See: [[rc://en/ta/man/jit/translate-hebrewmonths]] and [[rc://en/ta/man/jit/translate-names]])
Here understatement is used to emphasize that the Israelites must bring a suitable offering to Yahweh. "come to me without a proper offering" or "always bring an offering to me"