Reference for Shevuot 23:1
שאני קטורת דלא בר רעיה היא
[It may be retorted,] Incense is different, because it cannot be put to pasture.<span class="x" onmousemove="('comment',' Therefore the Beth din make a mental stipulation, but in the case of the regular daily offerings that are left over at the end of the year, since they may he put to pasture till they become blemished, and then redeemed, the Beth din would make no mental stipulations. The Rabbis who state the law of incense may, therefore, agree with R. Simeon in the case of the daily offerings. Who, then, are the Rabbis who disagree with him?');"><sup>1</sup></span> Well, then, the Rabbis [who State the law] of the red heifer.<span class="x" onmousemove="('comment',' Supra 11b. The red heifer may be redeemed unblemished.');"><sup>2</sup></span>