The discussion in the Gemara is, as always, challenging, and does not seem to provide a complete list of enactments. Nevertheless, it presents the following as representative of the whole, citing m.Zavim 5:12:
These render terumah (wave offering) unfit: He who eats food unclean in the first remove; and he who eats food unclean in the second remove; and he who drinks unclean liquid; he whose head and the greater part of whose body enters drawn water; and one who was clean on whose head and the greater part of whose body three logs of drawn water fall; and a scroll, and hands, and a person who has completed his rites of purification and awaits sunset to be completely clean [a tebul yom]; and food and utensils which have been made unclean by [unclean] liquids. (b.Shabbat 13b)
The terumah, though usually translated “heave-offering” or “wave offering” is not an offering per se as it was not burnt upon the altar. Rather, it was the dedication of an item or person to the service of the Temple. In the Talmud, it designates a free-will contribution, above and beyond the tithe, that the Torah calls on a man to offer to the Temple service. Though the Torah did not specify the amount that should be offered as terumah, Jewish law (m.Ter. 4:3) established the proper amount as being between one-sixtieth and one-thirtieth, depending on the piousness of the offerer. The terumah was not given directly to the Temple, but could be given to any priest (or, technically, any Levite), and the Pharisees were quick to rule that it should only be given to priests allied with their body. Food that the terumah had not been set aside for was called chullin, and could not be eaten by a Pharisee.
The contamination of food from which terumah was set aside was an incredibly important issue in Pharisaic Judaism, as we will see below.
Degrees of Uncleaness
At this point, we should define some terms. The terumah is commonly translated as the wave or heave offering, not burnt upon the altar of sacrifice but presented before the priests for service in the Mikdash. The word came to mean the tithe, not only of one’s grain and produce, but of all one’s income even down to one’s spices (cf. Mat. 23:23).
The word translated “unfit” is pasul, which is not to be confused with “unclean” (tamei). It is most likely the term rendered as koinos (profane, common, defiled, unholy; verb form, koinoo) in the Renewed Covenant Scriptures (cf. Mat. 15:11, Acts 10:15). Something that is “unfit” or “profane” could not be used for holy purposes, but could be used for other purposes without risking the spread of tumah.
An unclean object is called tamei, while one which could spread the condition of uncleanness by touch was called av hatumah, literally “the father (i.e., source) of uncleaness.” Tumah was considered to have multiple degrees of transmission, with corpse uncleanliness being the most severe, or first degree, of tamei. Contact with that which is tamei would render one tumah of one less degree. So, for example, a dead body is an av hatumah. The person who buried the body would be unclean to a secondary decree, sheni hatumah. If that person then shook hands with a third, the third person would be considered shlishi—unfit (pasul) to enter the Mikdash. Food that was shlishi is unfit (to a Pharisee, due to the sanctity of the dinner table) to be consumed, but incapable of spreading the condition of tumah any further. Priests were capable of sustaining a fourth degree of tumah, called revii, but other Jews could not.
In some cases, sheni uncleaness could only be transmitted through an object. For example, a woman who was niddah was an av hatumah, and anyone she directly touched would become pasul. However, those she touched were not capable of spreading the contamination further. But if she sat on a bed, the bed became sheni hatumah, and could transmit the contamination to a person so as to render them pasul. Unclean meat functioned the same way, being capable of rendering a vessel sheni hatumah or other food or a person touching it pasul.
Based on the above, the Pharisees reasoned that since food could be rendered pasul by being in contact with a source of uncleaness, and since the food on the table was sanctified by the practice of offering terumah from it (a reasoning not unlike what Paul employs in Romans 11:16), all such food must be eaten in a state of purity, or taharah.
Why the Concern?
It should be noted of course that it is a direct command of the Holy One “to make a distinction between the holy and the profane, and between the unclean and the clean” (Lev. 10:10). Furthermore, it is clear that tumah could indeed be transmitted by casual contact (Lev. 7:19, 11:32). By developing distinct degrees of impurity and defining what could spread uncleanness and what could not, the rabbis were fulfilling their proper role. However, in doing so, they actually increased the strictness of ritual purity well above the requirements of the Torah. The Gemara admits that this was the case when it points out that while Solomon decreed that hands may be tumah, he only did so in regards to sacrificial offerings; it was not until Hillel and Shimmai that hands were considered tamei for the terumah as well (b.Shabbat 15a). In fact, the Eighteen Measures raised the bar for ritual purity so high that at least some of them were criticized and repealed by the time R. Judah HaNasi penned the Mishnah (see b.Pesahim 19b).
How did they do so? Let us take, for example, the issue of unclean hands. The Gemara tells us that hands are assumed to be ritually unclean because they are constantly touching things. Therefore the hands had to be ritually washed before handling terumah and food from which the terumah had been set aside. In the case of the Pharisees, who recognized the corruption of the Temple and who were trying to import aspects of Temple-worship into their daily lives, the dinner table was considered a type of the altar. Thus, the ritual purity of the hands was considered as important for them as it was for priests serving in the Mikdash (cf. Exo. 30:21, Mark 7:3), to the point where it was said, “Whoever eats bread without washing his hands is as if he had sexual relations with a whore” (b.Sotah 4b). In other words, rulings affecting the defilement of the terumah would effect the observant Pharisee’s life on a daily basis. The Eighteen Measures would have the effect of splintering the people even more than they already were, to the point where even Pharisees could not eat with other Pharisees.
Fences of Fences
Several of the Measures involve adding more stringent rules to the rules of ritual purity, often only for the sake of discouraging unwanted behavior. For example, the rule that allowing the greater part of one’s body to enter drawn water would make one tumah came about to end a practice in which people would use fetid cave water for a mikveh (immersion pool) and then wash themselves afterwards. The rule that touching a sacred scroll made one tumah came about because the people began placing the terumah beside the scroll to show that both were holy, thus wasting the food.
Another example: The Torah declares that things which could survive being heated by fire could be purified by fire (Num. 31:23). It also implies that breaking an object, such as an earthen vessel, cleanses it (Lev. 6:28, 11:33, etc.). In order to avoid people “cleansing” objects by simply breaking and repairing them, the rabbis declared that repairing an object restored its previous tamei state—even if the “breaking” and “repairing” consisted of melting the object down (by fire, obviously) into its base metals and using those metals to create new objects (b.Shabbat 16b)!
Creating fences around the Torah is, of course, an old and noble impulse (cf. Pirke Avot 1:1). A Christian who, not wishing to risk becoming drunk, eschews alcohol altogether has built a fence around the commandment for himself. However, soon those fences either become sacrosanct and require fences of their own or they lead to unintended consequences of practice that it becomes necessary to regulate. For His part, Yeshua kept many of the rabbinic fences Himself (and taught His own, as in Mat. 5-7), but He did not suffer that His disciples should be judged as sinners for having a different practice or wider fence (cf. Mat. 12 and 15).
Here we see a similar confrontation occurring a generation earlier, with Shammai the driving force behind the creation of these new fences:
He who gleans grapes for the wine press — Shammai says, “The grapes have been rendered susceptible to uncleanness.” Hillel says, “The grapes have not been rendered susceptible to uncleanness.” Said Hillel to Shammai, “How come grapes have to be vintaged in a state of taharah (ritual purity) but olives don’t have to be gathered in a state of taharah?” He said to him, “So if you provoke me, I’ll make a decree of uncleanness also in the matter of gathering olives, too!” (b.Shabbat 17a)
Even here, we see that Shammai clearly sees himself as in charge over Hillel rather than Hillel’s equal. The very next line of Gemara, “They stuck a sword in the Beit Midrash,” amplifies for us again that the Measures were passed in a night of violence, under the threat of still more violence. It was the end result that this compromised Israel’s true mission to be a light to the Gentiles, as we will see next week.