Sukkah 49B

כשם שניסוכו בקדושה, כך שריפתו בקדושה. מאי משמע? אמר רבינא: אתיא ״קדש״ ״קדש״. כתיב הכא: ״בקדש הסך נסך״, וכתיב התם: ״ושרפת את הנותר באש לא יאכל כי קדש הוא״.

just as its pouring is in sanctity, so too must its burning be in sanctity. From where may it be inferred that this is referring to burning? Ravina said: It is derived by means of a verbal analogy between the term sanctity written with regard to libations and sanctity written with regard to leftover offerings. It is written here, with regard to libations: “In sanctity should you pour a libation” (Numbers 28:7), and it is written there, with regard to leftover offerings: “You should burn the leftovers in fire; they are not to be eaten, for they are sanctity” (Exodus 29:34). Through the verbal analogy it is derived that leftover libations must also be burned.

כמאן אזלא הא (דתניא): נסכים, בתחילה מועלין בהן. ירדו לשיתין ⁠— אין מועלין בהן. לימא רבי אלעזר בר צדוק היא, דאי רבנן, הא נחתו להו לתהום!

The Talmud notes: In accordance with whose opinion is that which is taught in this Mishnah? With regard to libations, initially, prior to being poured, one can misuse consecrated property with them, as is the case with all consecrated items. However, once they descended to the drainpipes, one does not violate the prohibition against misuse of consecrated property with them, because the mitzva was already fulfilled. Let us say that the Mishnah is in accordance with the opinion of R' Elazar bar Tzadok, who holds that the libations did not descend to the depths but would collect between the ramp and the altar and would be collected once every 70 years. As, if it were in accordance with the opinion of the Rabbis, how could the libations be misused? Didn’t they already descend to the depths through the drainpipes?