Reference for Pesachim 60:11
אמר רבא הני אגני דמחוזא הואיל ותדירי למילש בהו חמירא ומשהו בהו חמירא כבית שאור שחימוצו קשה דמי פשיטא מהו דתימא כיון דרויחא שליט בהו אוירא ולא בלעי קמ"ל:
And should you answer, [the interdict of] wine of nesek is [only] Rabbinical, [whereas that of] leaven is Scriptural, - surely whatever the Rabbis enacted, they enacted similar to Scriptural law? - Said he to him: This is used with hot [matter], while the other is used with cold.<span class="x" onmousemove="('comment',' And of course it has greater powers of absorption in the former case.');"><sup>19</sup></span> Raba B'Abba said in R'Hiyya B'Ashi's name in Samuel's name: All utensils which were used with leavened matter [hamez], cold, may be used with unleavened bread [mazzah], except a container of se'or, because it is strongly leaven.<span class="x" onmousemove="('comment',' And though the se'or placed therein was cold, yet it infects the vessel which in turn imparts a flavour of leaven to anything placed therein.');"><sup>20</sup></span> R'Ashi said: And a haroseth<span class="x" onmousemove="('comment',' A paste made of flour and vinegar, used as a sauce or relish.');"><sup>21</sup></span>