Where defendant, after he had been, by an instrument in writing, authorized by the owner of land to collect rents and make certain disposition thereof, accepted an order by such owner directing him to pay a specific portion of the accrued rents to the payee therein, this was a modification of the original agreement and binding upon defendant, though he might otherwise have been entitled to apply such rent to the satisfaction of claims held by him. Gray v. Barge, 50 N. W. 1014, 47 Minn. 498.