(Mishnah): A man can betroth himself or through a shaliach (a messenger).

A woman can accept betrothal, herself or through a shaliach.

A man can marry off his daughter when she is a na'arah (age 12 - 12 1/2) himself or through a shaliach.

If a man said, "Be betrothed to me with this date. Be betrothed to me with this one'' - if one of them is worth a perutah, she is betrothed; if not, she is not betrothed.

If he said, "...with this and with this'', if their total value is a perutah, she is betrothed.

If she ate them as he gave them, she is only betrothed if one of them is worth a perutah (as you cannot combine their value if she did not have them at the same time).

Question: What is the source to say that a person's shaliach is like the person himself?

Answer (R. Elazar): The pasuk states (Shemos 12, 6), "and the entire congregation of the assembly of Israel shall slaughter it in the afternoon.'' Could they all be slaughtering - but only one person is actually slaughtering? Rather, one person slaughters for all of them, as the shaliach of the person is like the person himself.

Question: Where is this taught?

Answer: The pasuk states (ibid, pasuk 3), "...and they shall take for themselves, each man, a lamb/kid for each father's house, a lamb/kid for the household''. Do they all take? One person takes for the entire household! Rather, from here we learn that a person's shaliach is like the person himself.

R. Yosi: The slaughtering here cannot be here working because of shelichus, since one is able to slaughter another's sacrifice without his knowledge (which would not be the case if he was a shaliach). Rather, it is act of the separating for several people that proves it...

If you will try to reject it by saying that person can separate another's Pesach offering without his knowledge (so it is not an act of shelichus, this is not a valid rejection....

...because R. Zeira said, citing R. Elazar, that a person may slaughter another's Pesach offering without his knowledge, but he may not separate it for him without his knowledge. So if the Torah told one person to separate for several, this proves that it is working using the concept of shelichus and a person's shaliach is like the person himself.