gross receipts
For purposes of this part, the term “gross receipts” means the total receipts from the sale, lease, or rental of property held primarily for sale, lease, or rental in the ordinary course of trade or business, and gross income from all other sources. In the case of commissions on the sale, lease, or rental of property, the amount taken into account for purposes of this part as gross receipts shall be the gross receipts on the sale, lease, or rental of the property on which such commissions arose.