Reference for Zevachim 26:2

א"ל ההוא מרבנן לרבא ושפיכת שירים והקטרת אימורין לא פסלה בהו מחשבה

One of the Rabbis said to Raba: Now does not intention disqualify at the pouring out of the residue and the burning of the emurim? Yet surely it was taught: You might think that intention is effective only in connection with the eating of the flesh.

Jastrow