Shevuot 40B

הודה במקצת קרקעות ⁠– פטור. במקצת כלים ⁠– חייב.

If he admitted to part of the claim about the land, he is exempt. If he admitted to part of the claim about the vessels, he is liable to take an oath.

טעמא דכלים וקרקעות ⁠– דקרקע לאו בת שבועה היא; הא כלים וכלים דומיא דכלים וקרקעות ⁠– חייב!

The Talmud infers: The reason he is exempt in the first cases is that the claim was for vessels and land, as a claim with regard to land is not subject to an oath; but if the claim was for vessels of one type and vessels of another type, or for wheat and barley, similar to the case of a claim for vessels and land in that the defendant admitted to owing one type and denied owing the other type, he is liable to take an oath.

הוא הדין דאפילו כלים וכלים נמי פטור; והא דקתני כלים וקרקעות ⁠– קא משמע לן דכי הודה במקצת כלים, חייב אף על הקרקעות.

The Talmud rejects the inference: No, it is possible that the same is true, i.e., that even if the claim was for vessels of one type and vessels of another type, and the defendant admitted to owing one type and denied owing the other type, he is exempt. And the reason that the Mishnah teaches specifically the case where the claim is for vessels and land is that this teaches us that in a case where the defendant admitted to a part of the claim with regard to the vessels, he is liable to take an oath concerning the land as well.

מאי קא משמע לן? זוקקין?! תנינא: ״זוקקין את הנכסים שיש להן אחריות לישבע עליהן״!

The Talmud asks: What is this teaching us? Does it teach the halakha that an admission to a part of the claim about vessels also binds the land to the oath? We learn this in a Mishnah in tractate Kiddushin (26a): When there is a claim against a person for movable property and land, and he is liable to take an oath concerning the movable property, the movable property binds the property that serves as a guarantee, i.e., land, so that he is forced to take an oath concerning it too.