A domestic stock or mutual insurer may borrow money to defray the expenses of its organization, provide it with surplus funds, or for any purpose of its business, upon a written agreement that such money shall be repaid only out of the insurer's surplus in excess of that stipulated in such agreement. The agreement may provide for the interest rate to be negotiated between the borrower and the lender, which interest shall or shall not constitute a liability of the insurer as to its funds other than such excess of surplus, as stipulated in the agreement. No commission or promotion expense shall be paid in connection with any such loan.
SDCL 58-5-108