R. Dostai says in the name of R. Meir, I heard that if there is an incline that cannot be swallowed, [we do not measure with the 50 Amah rope along the slope. Rather,] we are Mekader. (We measure in a way, explained below, that reduces or cancels out the vertical component of the distance. it is as if we drilled through the hill to measure the horizontal distance).

(Gemara) Question: What is the source of this?

Answer (Rav Yehudah): "Orech he'Chatzer Me'ah va'Amah v'Rochav Chamishim ba'Chamishim" teaches that we use a rope 50 Amos long.

Question: We need this to teach that we take [a square of 50 by] 50 Amos and surround it with [another square of] 50 Amos [cut into strips, to determine the largest area that may be Hukaf l'Dirah]!

Answer: It could have said 'Chamishim Chamishim.' Rather, it says "Chamishim ba'Chamishim" to teach both of these.

(Mishnah): We measure with a rope 50 Amos long, no more and no less.

(Beraisa): We do not use a shorter rope, for then the Techum would be too long. (The people who measure can stretch it.) We do not use a longer rope, for then the Techum would be too short (the rope would sag in the middle, for it is hard to hold it taut).

(Rav Asi): We use only a rope of Afsekima.

Question: What is this?

Version #1 - Answer (R. Aba): It is Nargila.

Question: What is Nargila?

Answer (R. Yakov): It is a fibrous substance under the surface of a palm tree with only one branch or bark.

Version #2 - Answer #1 (R. Aba): It is Nargila.

Answer #2 (R. Yakov): It is a fibrous substance under the surface of a palm tree with only one bark.

(Beraisa - R. Yehoshua): The best tool for measuring is an iron chain (it cannot be stretched). We cannot disqualify (Me'iri; alternatively - we must use) ropes because it says "uv'Yado Chevel Midah."

Question: It also says "uv'Yad ha'Ish Keneh ha'Midah"! (Also reeds should be good.)

Answer: That is for measuring gates.

(Rav Yosef - Beraisa): There are three kinds of ropes - Magag (a kind of reed), Netzarim (peeled willow) and flax:

Magag is used for Parah Adumah (since it is not Mekabel Tum'ah);

(Mishnah): They tied the cow with a rope of Magag, and put it on top of the woodpile [on which it is burned].

Netzer is used for Sotah;

(Mishnah): A Mitzri rope (i.e. Netzar - it alludes to the immorality she is suspected of) is tied above her breasts.

Flax is used for measuring.

(Mishnah): If there is a canyon...

Inference: Since it says 'we resume measuring', this implies that if it cannot be swallowed (it is too wide), we go to the side [where it is narrower], swallow it there, and resume measuring. (See Perush Chai diagram, Perek 5 number 70, in the English Charts section.)

Our Mishnah teaches like the following Beraisa;

(Beraisa): If we encounter a canyon when measuring:

If it can be swallowed by a rope 50 Amos long, we do so;

If not, we go to the side, swallow it there, and resume measuring.

If the canyon is crooked, he is Makdir up and down the sides.

If he reaches a wall, we do not pierce the wall. Rather, we estimate [its thickness] and continue.

Question: Our Mishnah said that we swallow it and resume measuring!

Answer: The Beraisa discusses a canyon that one can traverse, e.g. it slopes 10 Tefachim amidst four Amos [of slope. Therefore, we are Mekader.] The Mishnah discusses a canyon too steep to be traversed.

(Rav Yehudah): This is only if a plumb line (a weight hanging on a string, to determine what is vertical) does not descend [virtually] straight down (the edge is not so vertical). If it descends [virtually] straight down, we descend into the canyon and measure its width. (Since the edge is so steep, we ignore its horizontal component when measuring the Techum.)

Question: How deep may a canyon be [and still we swallow it when it is at most 50 Amos wide]?

Version #1 - Answer #1 (Rav Yosef): It may be [up to] 2000 Amos.

Question (and Answer #2 - Abaye - Beraisa): If it is 100 deep and 50 wide, we swallow it. If not, we do not.

Answer: Rav Yosef holds like Others:

(Beraisa - Others): Even if it is 2000 deep and 50 wide, we swallow it.

Version #2 - Answer #1 (Rav Yosef): It may be even more than 2000 Amos.

Question (Abaye): This is not like Chachamim or Others!

Answer: They discuss when the plumb line does not descend [virtually] straight down. Rav Yosef discusses when it does.

Question: How far from vertical must the plumb line be to say that it is not straight [and there is a limit to the depth until which we swallow]?

Answer (Avimi and Rami bar Yechezkeil's Beraisa): It must be four Amos away.

(Mishnah): If we encounter a hill, we swallow it and resume measuring.

Version #1 (Rava): This is only if it slopes 10 Tefachim amidst four Amos. If it slopes 10 Tefachim amidst five Amos (it is not so steep), we measure it properly [with a rope 50 Amos long, without swallowing it];

Version #2 - Rav Huna brei d'Rav Noson - (Rava): This is only if it slopes 10 Tefachim amidst five Amos. If it slopes 10 Tefachim amidst four Amos, we estimate it and continue [from the other side].

(Mishnah): ...As long as we do not leave the Techum (e.g. if the other side of the canyon is outside the Techum, we may not go there to gauge how far into the canyon the Techum extends. Rather, we gauge from the side. See Perush Chai diagram, Perek 5 number 73, in the English Charts section. Alternatively, when going to the side to swallow the canyon, we may not leave the Techum.)

Question: What is the reason?

Answer (Rav Kahana): This is a decree, lest people say that [since the measurers came to this place, surely] the Techum extends to here.

(Mishnah): If we cannot swallow it...

(Beraisa): To be Mekader, the person below holds the rope near his heart, and the one above holds it near his feet.

(Abaye): We have a tradition that a rope four Amos long is used to be Mekader.

(Rav Nachman): We are not Mekader when measuring the Techum of an Ir Miklat or to bring Eglah Arufah, because they are mid'Oraisa.

Version #1 (our text) (Mishnah): We measure only from a Mumcheh. (This will be explained);

Version #2 (Rashi) (Mishnah): Only a Mumcheh (expert) may measure. (end of Version #2)

If a Techum (e.g. to the east) was measured in two places (e.g. from the northeast and southeast corners), and one of them extends further [east] than the other, we follow the larger Techum;

If a larger Techum was measured for one and a smaller Techum for another, we follow the larger. (This will be explained.)

Even a male or female slave is believed to say 'the Techum extends to this place', for Chachamim enacted Techumim to be lenient, and not to be stringent.