Meilah 4:2-3

Meilah 4:2

Five things in a burnt offering can combine: the flesh, the fats, the flour, the wine and the oil. Six things in a thanksgiving offering can combine: the flesh, the fats, the flour, the wine, the oil and the bread. Trumah, the trumah of tithes, trumah of the tithes from doubtfully-tithed produce, challah and first-fruits can all combine to form the minimum volume necessary for prohibition and to obligate one in paying a fifth.

Meilah 4:3

All kinds of piggul can combine with one another; all kinds of nosar can combine with one another; all kinds of neveila can combine with one another; all creeping creatures can combine with one another; the blood and flesh of creeping creatures can combine with one another. Rabbi Yehoshua said that the general rule is that all things that are alike in the duration of their impurity and that have the same minimum size can combine with one another. Those things that are alike in impurity but different in minimum size, or alike in minimum size but different in impurity, or those that are different in both of these aspects, do not combine with one another.