Pesachim 19a, b

While today's daf seemed shorter than most on first glance, it covers a number of concepts and halachot.  It is true that I am understanding more each day about these very complex ideas.

The rabbis attempt to narrow their descriptions of degrees of impurity.  They debate about what holds first and second degree impurity - and thus what holds fourth or even fifth degree impurity.  At fourth and fifth degrees of ritual impurity, objects/beings are disqualified.  The rabbis also debate about which foods/animals/items are affected by impurity.  Consecrated items may retain fifth degree impurity, for example, while terumah may retain only fourth degree impurity.  

As an aside, I am confused about the differences between consecrated items and terumah.  Terumah is what has been collected to be given to the priests.  What are consecrated items if not items that have been given special status?  Perhaps consecrated items include 'concepts', like the nasir who consecrates her or himself to G-d.  But this definition does not help me understand how consecrated items would retain ritual impurity.

An interesting conversation notes that the rabbis cannot find proof that Rabbi Yosei refers to an a fortiori statement about fourth and fifth degree impurity with relation to terumah and consecrated items. Without proof, the rabbis would be suggesting that the halacha will be accepted because of a lack of proof.  We are told that either Rav Ahi or Rav Kahana left the study hall to think about this.  Steinsaltz explains that Sages would remove themselves from other students to let them continue their learning.  They would then consult with others not present who had memorized the mishna and/or baraita.  And so, on returning, this Rav was able to prove that Rabbi Akiva disagreed with the suggestion.

Which introduces a new concept: a vessel containing items joins those items into a single unit.  Thus a bowl of pears where one pear is impure creates an impure vessel filled with impure pears.  The rabbis provide a number of examples of this concept in action, which is a rabbinic ruling.

In addition to using the example of a needle found stuck in a cow, a number of interesting points are discussed in daf b:

• Items that cannot answer a question are assumed to be ritually pure (because a person would have to have touched those items to something to impart ritual impurity)
• Hands are usually assumed to be impure if not washed or submerged
• Hands do not retain impurity in the Temple
• Spit on the ground generally is considered to be impure
• Spit in Jerusalem is considered to be pure
• Spit on the street is assumed impure as people of ritual purity walk on the walkways
• Spit on the walkways is assumed to be pure
• During chagim, it is reversed: spit on the street is assumed pure and on the walkways is assumed impure
• Vessels found near the mikvah are considered pure (though this is hotly debated)
• Rav Ashi clarifies that items found in the public domain are assumed to be ritually pure

I'm not sure why there is so much talk about vessels.  Maybe I don't understand what a vessel is, or how ubiquitous vessels were in antiquity.  I think of a vessel as a bowl or a pot.  But perhaps vessels were everything: plates, bowls, bags, basins, pots, baths, cups, etc.  

And speaking of things that I don't understand, the word utensil, "mana", is challenging to me as well. Apparently this needle was a utensil.  I don't appreciate the breadth of this category.  Are utensils simply any object that can help us do something with another object?  For example, a spoon could be a utensil, but a stick could be a utensil, too...?

So so so many questions...