Where defendants gave plaintiff an option to effect a sale of coal properties, if sold within a certain time, on a stipulated commission, and agreed to assist plaintiff in the sale thereof, defendants will not be heard to say that a sale to one with whom plaintiff was negotiating, made during the continuance of the option, was the result of their independent efforts. Wells v. Rocking Valley Coal Co., 137 Iowa, 526, 114 N. W. 1076. See also Sec. 841.

See. 861a. Since oral promise to pay commission is not binding, oral promise to make contract can not operate as estoppel to deny right to commission.

Since an oral promise to pay a commission for the sale of land is not binding, an oral promise to make a contract can not operate as an estoppel to deny broker's right to a commission, since the broker had no right to rely on it. Edwards v. Laird, 134 P. 365, 22 Cal. App. 398; Connor v. Biggins, 132 P. 849, 21 Cal. App. 756.