Maaser Sheni 2:4-5

Ma’aser Sheini 2:4

Vicia (flowering legumes mainly used as animal feed) of second tithe must be eaten before they mature (while they are still fit for human consumption) and they may be brought into Jerusalem and removed again (because they’re not considered human food under most circumstances). If they become ritually impure, Rabbi Tarfon says to put them in pieces of dough too small to be rendered unclean, while the Sages say they can be redeemed like any other second tithe rendered unclean. Beis Shammai say that vicia of terumah must be soaked and rubbed in a state of ritual purity (so as not to render the terumah unclean) but that they may be fed to animals in a state of impurity. Beis Hillel say they must be soaked in a state of ritual purity but they may be rubbed and fed to animals in a state of impurity. Beis Shammai say they must be eaten without coming into contact with water (to avoid the transmission of ritual impurity). Rabbi Akiva says that anything done with them may be done in a state of ritual impurity (even soaking).

Ma’aser Sheini 2:5

If secular money and second tithe money were scattered together, whatever one picks up goes to second tithe until he has reached the amount that was in the second tithe money; the rest is non-sanctified. If he scooped up all the money at once, he divides it according to the percentage that was second tithe. The general principle is that when one picks up the coins individually, they go to second tithe first; when they are all mixed together, one divides them by percentage.