[If he said,] ‘‘I take upon myself [to bring] a minchah-offering from barley,’’ he must bring one from wheat. [If he said,] ‘‘coarse flour,’’ he must bring fine flour; ‘‘without oil and frankincense,’’ he must bring it with oil and frankincense; ‘‘half an issaron,’’ he must bring an issaron; ‘‘an issaron and a half,’’ he must bring two. R’ Shimon exempts [him] because he did not donate in the manner of those who donate.