Mishnayos Terumos Perek 5 Mishnah 1

סאה תרומה טמאה שנפלה לפחות ממאה חולין – for impure heave-offering also is neutralized with one and one-hundred.

ירקבו – for it is impossible for a Kohen to consume it because it is impure heave-offering. And surely as it is not taught in the Mishnah "ידלקו" /”that it should be burned,” tbecause we are concerned that perhaps that if he kindles them, they would come to a stumbling block/snare and that they would come to eat from it, because it is considered a mixture of heave-offering and unconsecrated produce (which is forbidden to non-priests), people would treat it lightly and they would not be careful about it all that much.

אם טהורה היתה אותה סאה – and also the unconsecrated produce should be sold to the Kohanim at the [low] cost of the Terumah/heave-offering, for its worth is less, because there aren’t many who consume it, if it is defiled, it is not fit for eating.

חוץ מדמי אותה סאה – for it is necessary to give it to the Kohen.

ואם למעשר ראשון – pure [First Tithe] whose tithe had not been taken from it, the Terumah of the tithe that fell, he should request from the Levite that he should exchange them with unconsecrated produce, and the Levite should make them the Terumah of the tithe on his eatables forbidden pending the separation of sacred gifts..

ואם למעשר שני והקדש טהורים נפלה – he should redeem them and consume the monetary worth of the tithe in Jerusalem, and that mixture of heave-offering and unconsecrated produce should be sold to the Kohanim at the monetary value of the heave-offering less the value of that Seah.

ואם טמאים היו – the unconsecrated produce and the First Tithe into which pure heave-offering fell, for now, he is not able to produce Terumah of the tithe on another place, he separates upon it Terumah of the Tithe and sells them to Kohanim, and the Kohanim can eat them in small bits, in explanation, in a dry condition, like (Joshua 9:12 – not quoted correctly by Bartenura): “[This bread of ours….and see] how dry and crumbly it has become.”

או קליות – just as that the ritually pure heave-offering was not made fit to receive Levitical uncleanness , and all food-stuffs that do not have liquid come upon them from the seven liquids (see Tractate Makhshirin, Chapter 6, Mishnah 4: dew, water, wine, oil, blood, milk, the honey of bees), it is not fitted to receive Levitical uncleanness.

או ילושו במי פירות – as, for example, mulberry juice and pomegranates that are not made fit [to receive Levitical uncleanness].

או יחלקום לעיסות – that he will give less than an egg’s bulk in each [little] lump of dough/started dough, and food-stuffs that are less than an egg’s size does not receive ritual impurities of eatables and it doesn’t defile ritual defilement of eatables, and if someone asks what is the difference from a Seah of ritually impure heave-offering that fell into ritually pure unconsecrated produce, that we state that it should rot, because it makes everything heave-offering and is considered like ritually impure and heave-offering that were mixed and would be forbidden to be eaten? But one can say that they are not similar, for above, this unconsecrated produce became like heave -offering, to be prohibited to foreigners (i.e., non-priests) on the strength of the ritually impure heave-offering, therefore, for Kohaim also, they are forbidden according to the law of ritually impure heave-offering/Terumah, but those unconsecrated produce of here, are not made into heave-offering, other than from the strength of pure heave-offering, therefore, they are permitted to Kohanim like ritually pure Terumah.