Except as provided in subsection (k), if any fuel on the sale of which tax was imposed under paragraph (2) or (3) of section
4041
(a) or section
4041
(c) is used on a farm for farming purposes (within the meaning of section
6420
(c)), the Secretary shall pay (without interest) to the purchaser an amount equal to the amount of the tax imposed on the sale of the fuel. For purposes of this subsection, if fuel is used on a farm by any person other than the owner, tenant, or operator of such farm, the rules of paragraph (4) of section
6420
(c) shall be applied (except that “liquid taxable under section
4041” shall be substituted for “gasoline” each place it appears in such paragraph (4)).