Question: If the height was less than 10 Tefachim, one must carve [a cavity in the ground to make the height 10]. How much [width] must he carve?

Answer #1 (R. Acha): It must be four Amos, the Shi'ur of a Mavuy.

Answer #2 (R. Yosah): It must be a four Tefachim, the [minimum] Shi'ur of an [important] place.

(Rav Acha bar Yakov citing R. Yosah citing R. Yochanan): He makes a furrow at the opening of the Mavuy 10 deep and four wide and permits the Mavuy, whether inside or outside. [It permits outside] only if it is within three Tefachim of the walls of the Mavuy [due to Lavud];

Even the one who says there [about partial Koros that come out of the walls, Lavud applies to up to] four, he agrees here [that it is only] within three. There it is inside the Mavuy. Here it is outside the Mavuy.

If one made a fence in the opening of the Mavuy, 10 tall and four wide, it permits the Mavuy, whether it is inside or outside;

If there was a mound [outside the Mavuy], if [the slope] rises 10 Tefachim amidst [a horizontal distance of] three [Amos, it is not steep enough to be considered a wall, so it is not considered a Lechi, so the Mavuy] needs a Korah. If not [it rises 10 Tefachim in less than three, it is considered a Lechi, so] it does not need [a Korah].

Some teach [that it depends on whether or not it rises 10 Tefachim amidst] four [Amos].

The one who says amidst three is Rabanan. The one who says amidst four is R. Meir. (PNEI MEIR, HA'GAON RAV C. KANIEVSKY, SHLITA - the Gemara knew that they argue about this. OHR SOMAYACH (Hilchos Shabbos 17:4) says that we infer the argument from their opinions about measuring the Techum when it passes through hills.)

If there was an incline in the middle of the Mavuy - [if it rises 10 Tefachim within three or four, according to Rabanan or R. Meir], for those on top it is considered a furrow, and for those on bottom it is considered a fence [so both of them are permitted].