[66a - 20 lines; 66b - 42 lines]
1)[line 1]תהו בהTAHU BAH- they contemplated and delved into it (Rebbi Yochanan's ruling)
2)[line 4]לאLO- Rebbi Yochanan did not compare renting space in the Chatzer from a Nochri to making an Eruv in the Chatzer stringently. He only compared them leniently (as follows), for all laws of Eruvin are ruled leniently. (RASHI)
3)[line 6]ומה מערב אף שוכר אפילו שכירו ולקיטוU'MAH ME'AREV... AF SOCHER AFILU SECHIRO U'LEKITO- just as a Jew hired by a Nochri obviates the need to rent space from the Nochri because he fills in for his employer, a Nochri hired hand may fill in for his employer and rent out his employer's space.
4)[line 7]ומה מערב חמשה שוכר... נמי חמשהU'MAH ME'AREV CHAMISHA... SOCHER NAMI CHAMISHA...- Just as any one of five Jews living in a Chatzer who wish to make an Eruv with a neighboring Chatzer may represent the residents of his Chatzer for the purposes of making the Eruv, so may he represent his Chatzer to rent space from a Nochri resident on behalf of the others.
5)[line 10]תהי בה רבי אלעזרTAHI BAH REBBI ELAZAR- into the case where certain Chachamim rented from a Nochri on Shabbos and then proceeded to nullify his Reshus
6a)[line 14]שאוסריןOSRIN- they prevent the other from carrying on Shabbos when they have not made an Eruv together
b) ומערביןU'ME'ARVIN- and have the capability of joining together in an Eruv (before Shabbos)
7)[last line]לוגר מאתמולLOGAR ME'ESMOL- let them rent from the Nochri on Erev Shabbos (and since this is possible, why was this case categorized as "Ein Me'arvin"?)
66b----------------------------------------66b
8)[line 1]וקתני אוסרין ואין מערבין אין מבטליןU'KA'TANI OSRIN V'EIN ME'ARVIN, EIN MEVATLIN- That is, it is not permitted to rent from the Nochri on Shabbos when he arrives in the Chatzer on Shabbos, but not for the reason suggested earlier (65b) by Rebbi Asi. It is not that Sechirus may not be done on Shabbos ("Socher k'Me'arev"), but that Bitul (which is necessary after the Sechirus) cannot be performed, since Bitul works only when there was an option to make an Eruv in the Chatzer at the beginning of Shabbos.
9)[line 3]אמר רב יוסף לא שמיע לי הא שמעתאAMAR RAV YOSEF LO SHEMI'A LI HA SHEMAITSA- Rav Yosef became sick and forgot much of his learning. His student Abaye reminded him of what he himself had taught.
10)[line 5]אין ביטול רשות מחצר לחצרEIN BITUL RESHUS ME'CHATZER L'CHATZER- In the event that the inhabitants of a courtyard did not set an Eruv Chatzeros before Shabbos, carrying may still be permitted if Bitul Reshuyos is performed. This is accomplished as follows: If none of the residents of a courtyard made an Eruv, all of the inhabitants of the courtyard may nullify their domains in favor of one of the inhabitants. All of the houses/courtyards in the area are considered the private domain of the person chosen. If some of those in the courtyard made an Eruv together, those who did not may nullify their domains in favor of the collective domain of those who made an Eruv. Shmuel is qualifying this allowance of the Chachamim as follows: This only applies to inhabitants of one Chatzer who prevent one another from carrying without an Eruv. The inhabitants of neighboring Chatzeros who forgot to make an Eruv and wish to carry from one to the other do not have the option of nullifying the Reshus of one Chatzer to the other.
11)[line 6]ואין ביטול רשות בחורבהEIN BITUL RESHUS B'CHURVAH- If a derelict building is sandwiched between two houses, and the inhabitants of each house utilize it for their own purposes, they must make an Eruv in order to carry within the Churvah on Shabbos. If they have not, they do not have the option of nullifying one of the houses to the other on Shabbos in order to give the Churvah the status of a Reshus haYachid.
12)[line 15]שהמבוי לחצירות כחצר לבתיםSHE'HA'MAVOY L'CHATZEROS K'CHATZER L'BATIM- Shmuel inferred from this wording that a Mavoy is only considered such when it has a minimum of two Chatzeros opened into it, each with a minimum of two houses contained within it (see 73b).
13)[line 31]נתנו עירובן בחיצונהNASNU EIRUVAN B'CHITZONAH- The normally accepted practice when joining two Chatzeros with an Eruv was for one of the Chatzeros to place the same Eruv that it used to permit carrying within its own Chatzer into the other Chatzer. Thus the one Eruv accomplished two purposes (RASHI).
14)[line 33]שתיהן אסורותSHETEIHEN ASUROS- that is, Shmuel rules that in such a case a Bitul Reshuyos is not allowed on Shabbos.
15)[line 35]נתנו עירובןNASNU EIRUVAN...- the Gemara is now quoting from the Bereisa in order to explain it line by line.
16)[line 37]ליתא לערובייהו גבייהוLEISA L'ERUVAIHU GABAIHU- that is, since the Eruv is not in the inner courtyard, closing the gate between it and the outer one is not an option, and will not allow the people of the inner courtyard to carry (see Chart/Insights)
17)[line 39]איכא פנימית דאסרה עלייהוIKA PENIMIS D'ASRAH ALAIHU- That is, the people of the outer courtyard do not have the option of "closing the gate" between the two courtyards and saying, "We only joined you in our Eruv for our mutual benefit, and not to cause us harm," since they had no choice but to make a joint Eruv. This is because the people of the inner courtyard trample through the outer courtyard on the way to Reshus ha'Rabim, and are therefore considered bona fide residents of the outer courtyard. Due to this the outer courtyard cannot make an Eruv without them. (See Insights.)
18)[line 39]ליבטיל לבני פנימיתLIVTIL LI'VNEI PENIMIS- that is, to the members of the inner courtyard as well
19)[last line]איכא חיצונהIKA CHITZONAH D'ASRAH ALAIHU- The residents of the outer Chatzer are considered to dwell in the inner one as long as their Eruv is present there. (This is known as "Hergel Eruv.")