Eruvin 5:5 - 5:6

אין מודדין אלא מן המומחה – a person who is a specialist in measuring, and the Gaon explained that the word מומחה is the language from (Numbers 34:11): “and abut on the eastern [slopes] of the Sea of Chinnereth/Kinneret,” meaning to say that they intent to measure the bottom ab initio from the place that is level and straight, in order that they would not need to perforate.

ריבה למקום אחד ומיעט למקום אחר – that they found signs of this [Sabbath] limit long and protruding corresponding to the signs of the [Sabbath] limit in the corner that is opposite it.

שומעין למקום שריבה – and we remove the shorter measurement, that is corresponding it, because it did not initially stretch the rope all the way. And it is taught in the Tosefta [Eruvin 4:`6 – in the Lieberman edition – but it is in chapter 6 according to the Erfurt manuscript] that he must stretch it with all of his strength [and measure].

ריבה לאחד ומיעט לאחר – this is what he said: if there was a greater distance for one [expert] and a lesser distance for the other [expert], for the two people who measured were experts – this one had a greater distance and the other a lesser distance.

עיר של יחיד – as, for example that one person acquired it all and he rents out all of its houses to the people that are living there, and afterwards, it becomes the property of many.

מערבין את כולה – in the manner that they create a symbolic community of residence (i.e., an Eruv) when it belonged to a single individual that didn’t require a remnant.

אין מערבין את כולה – for it is forbidden to make an Eruv for a city/town belonging to many if he doesn’t leave known houses without an Eruv, for this remnant is a recognition that the reason is because of an Eruv, so that it would not forget the laws of the public domain. And this is the case, since it [belonged] to the group, and required a remnant even though that now it would be judged as that of an individual as at first.

אלא אם כן עשה חוצה לה – a remnant that was not made into a symbolic community of residence with the rest of the city/town, but it something remarkable that comes to teach us that even a remnant of something outside it has an effect on the rest of the city/town.

כעיר חדשה שביהודה – there was a city in Judah and its name was Hadasha, and there not there other than two temporary residents/inhabitants , and this is the smallest city/town that is in all of land of Judea and it was the remnant to a larger city that is adjacent to it, and this is measurement of the remnant that one needs to leave over in a city/own that they did not make into a symbolic community of residence (i.e., Eruv) with the others because of recognition.

רבי שמעון אומר שלש חצירות כו' – and the Halakhic decision is that even one house in one courtyard is a remnant. But a city that doesn’t have other than only one opening even if was of many [people], there is no need for remnant.