משנה על מעשר שני 2:1

One who exchanges a sela from second tithe in Jerusalem: Beth Shammai says: “Copper coin for the whole sela.” And Beth Hillel says: “Silver for one shekel and copper coin for one shekel.” The disputants before the Sages say: “Silver for three denars and copper coin for one denar.” Rabbi Akiva says: “Silver for three denars and for the fourth silver, copper coin.” Rabbi Tarfon says: “Four aspers in silver.” Shammai says: “He must leave it in the shop and eat on the credit thereof.”

Rabbi Shimon says: one may not anoint oneself with oil of second tithe in Jerusalem. But the sages allow it. They said to Rabbi Shimon: if a lenient ruling has been adopted in the case of terumah which is a grave matter, should we not also adopt a lenient ruling in the case of second tithe which is a light matter? He said to them: No; a lenient ruling has been adopted in the case of terumah though it is a grave matter, because in terumah we have adopted a lenient ruling also with regard to vetches and fenugreek, but how can we adopt a lenient ruling in the case of second tithe though it is a light matter, when we have not adopted a lenient ruling in second tithe with regard to vetches and fenugreek?

Fenugreek of second tithe may be eaten when it is still tender. Fenugreek of terumah: Bet Shammai says: whatever is done with it must be done in a state of purity, except when it is used for cleansing the head. But Bet Hillel says: whatever is done with it may be done in a state of impurity, except soaking it in water.