Zevachim 31B

הא לאכול ולאכול דומיא דלאכול ולהקטיר, והיכי דמי ⁠– בשני בני אדם; מצטרף! שמע מינה.

It can be inferred that if one had intent to eat and to eat in a manner similar to a case of intent to eat half an olive-bulk and to burn half an olive-bulk; Abaye interjects: And what are the circumstances of such a case? It is a case with two people, i.e., where each one will consume half an olive-bulk. Abaye continues with the conclusion of his statement: Then the two halves join together. The Talmud concludes: Learn from it that this is so.

בעי רבא: חישב לאכול כזית ביתר מכדי אכילת פרס, מהו? לאכילת גבוה מדמינן ליה, או לאכילת הדיוט מדמינן ליה?

Rava raises a dilemma: If one had intent to eat an olive-bulk in more than the period of time it takes to eat a half-loaf of bread, what is the halakha? Do we equate the consumption of offerings to the consumption of the Most High, i.e., the burning of offerings on the altar, for which there is no maximum allotted time? Or do we equate it to the consumption of an ordinary person, for whom consumption slower than this rate is not considered eating?

אמר אביי, תא שמע: לאכול כחצי זית ולהקטיר כחצי זית ⁠– כשר, שאין אכילה והקטרה מצטרפין. טעמא דלאכול ולהקטיר, הא לאכול ולאכול ⁠– מצטרף; והא הקטרה ביותר מכדי אכילת פרס הוא!

Abaye said: Come and hear a proof from the Mishnah: If his intent was to eat half an olive-bulk and to burn half an olive-bulk not at the appropriate time or in the appropriate area, the offering is fit because eating and burning do not join together. One may infer that the reason the offering is fit is that he had intent to eat and to burn the offering. But if he had intent to eat half an olive-bulk at the normal rate and to eat half an olive-bulk in the time it takes to burn half an olive-bulk, the two would join together. But the burning of an olive-bulk of an offering can take more than the time it takes to eat a half-loaf of bread. It therefore seems that there is no upper limit on the time in which one is considered to have consumed an offering.