Explanation: This Mefivoshes was Sha'ul's son.

Explanation (R. Tam): He was David's Rebbi, like it says in Berachos (4a) that he embarrassed David in Halachah.

The text there says "his name was not Mefivoshes, rather, Ish Ba'al." Mefivoshes ben Sha'ul is called Ish Ba'al in Divrei ha'Yamim.

Alternate text: The text in Seforim [there] is "Ish Boshes is his name."

Rejection: We do not find anywhere that Ish Boshes is called Mefivoshes;

Also, Ish Boshes was killed at the beginning of the reign of Beis David, before the episode with the Giv'onim;

Suggestion: Mefivoshes the son of Yehonason was David's Rebbi.

Rejection: We do not find anywhere that he is called Ish Boshes or Ish Ba'al. (The Gemara said that David's Rebbi Mefivoshes was really Ish Ba'al.)

Question: Why didn't David show honor to his Rebbi and request mercy for him, that the Aron not absorb him?

Answer: Perhaps he requested, but he was not answered.

Note: In Berachos, the Maharsha says that Mefivoshes ben Yehonason was David's Rebbi, and that the text says that he is called Meriv Ba'al. If so, David requested mercy for his Rebbi, and he was answered.

Citation: The Midrash (Bamidbar Rabah 8) expounds "El ha'Tzur" - she justified Hash-m's decree, and said "ha'Tzur Tamim Pa'alo."

Explanation: This is a measure of employment. "Dun" refers to measures, like it says in Bava Basra "they called it Dun Papa." (In our texts, it says there "Ruz Papa.")

Explanation #1 (Rashi): At the beginning of our Sugya, Rashi explained that he decreed against marrying them, like it says "veha'Giv'onim Lo mi'Bnei Yisrael Hemah...", i.e. it is improper that they cling to Yisrael;

Now we ask that Moshe decreed slavery on them, and they are forbidden due to "Lo Yihyeh Kadesh";

We answer that Moshe decreed only for that (his) generation, and Yehoshua decreed only when the Mikdash stands.

Explanation #2: We could say that they were never forbidden due to "Lo Yihyeh Kadesh", since he did not decree on them slavery even when there is no Mikdash;

David decreed against marrying them. He did not put servitude on them for all generations.

Support: The Nesinim do not have the status of slaves.

Source #1: A Mishnah (Kesuvos 29a) says that if one has Bi'ah with [rapes or entices] a [Na'arah Besulah] Nesinah, she receives a fine;

If one has Bi'ah with a slave, the Mishnah says that there is no fine.

The Yerushalmi says that this is even if she was guarded, and [we know that] she never had Bi'ah.

Source #2: If they had the status of slaves, it would be forbidden for Nesinim and freed slaves to intermarry, for a freed slave may not marry a Shifchah;

We say that a half-slave, half Bnei Chorin may not marry a Shifchah (Gitin 41a, because his half that was freed is forbidden to her).

It says in Kidushin (69a) that freed slaves and Nesinim may intermarry.

Explanation #3: The Gemara asks that he did not decree actual slavery on them. Presumably, he also decreed not to marry them, for it is improper to marry them, since they appear like slaves;

We can say that also David decreed slavery on them in order that people not marry them.

Support #1: Now it is a proper question that Moshe decreed about them.

Support #2: It is fine that we say that in the days of Rebbi, they wanted to permit the Nesinim, to uproot the servitude from them. Through this, it would be permitted to marry them.

We conclude that no one can permit the share of the Mizbe'ach. Since there remains on them servitude of the Mizbe'ach's share, it is improper to cling to them.

This is unlike R. Chiya bar Aba, who says that the Mizbe'ach's share is permitted when there is no Mikdash;

If they would uproot Yisrael's share, they would be totally permitted, and no servitude of the Mizbe'ach would take effect on them even when it will be rebuilt.

Objection (R. Tam): Mid'Oraisa, there is a Lav "Lo Sischaten Bam", like Rava concluded above (76a) that marriage applies to them after conversion;

A Mishnah (Makos 13a) teaches that there are lashes for one who has Bi'ah with a Mamzeres or Nesinah.

Answer: We can say that Nesinah was taught only because it is normally taught with Mamzeres (but really, there are no lashes for a Nesinah).

Support: We must say so according to Rava's Hava Amina that after conversion, they have no [Isur of] marriage;

Everywhere it discusses after conversion, i.e. regarding a fine, and in the Mishnah (Kidushin 69a).

Explanation #4 (R. Tam): David decreed servitude on them. (Mid'Oraisa, marriage is forbidden.)

Implied question: Above, it says [that David decided who is] proper to cling with Yisrael. (This implies that there is no Torah Isur of Nesinim!)

Answer: This means [that they are not proper] to be free like Yisrael. Marriage is forbidden mid'Oraisa.

Implied question: It says in the days of Rebbi, they sought to permit the Nesinim!

Answer: This does not mean to permit marriage, rather, to uproot the servitude;

Rebbi said that we cannot permit the Mizbe'ach's share, therefore we should not permit even our (Yisrael's) share, lest the Mizbe'ach's share be forgotten;

He argues with R. Chiya bar Aba, who says that when there is no Mikdash, the Mizbe'ach's share is automatically permitted. No [act] is needed to permit it;

If the servitude were totally uprooted, it would not take effect on them again.

Question: Since the Torah forbids Nesinim due to Lo Sischaten Bam, why is a freed slave permitted to them, but he is forbidden to a Shifchah due to Lo Yihyeh Kadesh?

Answer: We can learn the Lav of Lo Sischaten Bam from other Pesulei Kahal such as Mamzer, Amoni and Mo'avi, who are permitted to Kahal Gerim;

We cannot learn the Lav of Lo Yihyeh Kadesh, for Kedushin does not take effect on a Shifchah. She is unlike other Pesulim.

Question: Why is a Mamzer permitted to a Shifchah? The Mishnah (Kidushin 69a) permits a Mamzer to marry a Shifchah even l'Chatchilah! This is clear from the Gemara there.

Answer (R. Tam): Lo Yihyeh Kadesh does not apply to a Mamzer. His very inception is from Kedeshos, i.e. an Isur in which Kidushin does not take effect. This is not the place to elaborate.

Implied question: This is like being Mevatel the decree of an earlier Beis Din! (A latter Beis Din can do so only if it is greater in Chachmah and number.)

Answer: [There is no problem of this, because] Hefker of Beis Din is Hefker.

Explanation: Granted, if you will say that we discuss when he married a Yisraelis, even though she can do Yibum, it is not difficult why he does not do Yibum, for he is forbidden to her, for he is a Petzu'a Daka;

Since we said that he does Chalitzah, we said that they do Chalitzah to his wife.

However, since [you say that] we discuss a convert, he (the Petzu'a Daka himself) should be able to do Yibum!

Question: Since R. Yehoshua discusses a convert, why did he mention Choletz?

Answer #1 (Rashi): He holds that Kahal Gerim Ikri Kahal. (Therefore, Yibum is forbidden.)

Objection: If so, why did he say "I cannot explain?"

He can infer that since they taught him that he does Chalitzah and they do Chalitzah to his wife, and they did not teach him that he does Yibum and they do Yibum [to his widow], this shows that a Seris Adam does Chalitzah and they do Chalitzah [to his widow];

If [they taught him about] a Seris Chamah, even Yibum would be permitted!

Answer #2: R. Yehoshua mentioned he does Chalitzah and they do Chalitzah, for parallel structure with the [latter] clause he said "he does not do Chalitzah and they do not do Chalitzah [to his widow].

He could not have taught "he does not do Yibum and they do not do Yibum [to his widow], for this would imply that Yibum is forbidden, but Chalitzah is permitted!

Note: There is no Isur of a unnecessary Chalitzah. Tosfos means that it would imply that the Seris can do Chalitzah to exempt her, even if he has fertile brothers.

Distinction: However, R. Akiva could have taught "he does not do Yibum and they do not do Yibum [to his widow]";

Since he explained the reason, because he was never Kosher, automatically we know that he cannot do Chalitzah;

However, since R. Yehoshua discussed Chalitzah, also R. Akiva did.

Explanation: This is like R. Akiva, who says that a Seris Adam does Chalitzah or Yibum.

Question: Perhaps regarding this the Tana holds unlike R. Akiva, who equates Chayavei Lavin to Chayavei Kerisos!