D.C. Code § 42-607

A covenant by a grantor, in a deed of land, “that he has done no act to encumber said land,” shall be construed to have the same effect as if he had covenanted that he had not done or executed or knowingly suffered any act, deed, or thing whereby the land and premises conveyed, or intended so to be, or any part thereof, are or will be charged, affected or encumbered in title, estate, or otherwise.