One who gives [food] to his mother-in-law must tithe that which he gives her and that which he takes back from her because she is suspected of exchanging that which spoils. R’ Yehudah said: She desires the well-being of her daughter and is embarrassed on ac-count of her son-in-law. R’ Yehudah agrees in the case of one who gives his mother-in-law [produce during] sheviis that she is not suspected of exchanging [it and thus] feeding her daughter sheviis [produce].

[If] one purchases fruit from someone who is not trusted regarding tithes, and forgets to tithe it, and asks [the seller] on the Sabbath, he may eat [the fruit based] on [the seller’s] word. [With] the onset of darkness at the departure of the Sabbath, he may not eat [it] until he separates tithes. [If] he did not find [the seller], [and] someone [else] who is not trusted regarding tithes said [to him]: ‘‘[The fruit] is tithed,’’ he may eat [it based] on his word. [With] the onset of darkness at the departure of the Sabbath, he may not eat [it] until he separates tithes. [Regarding] terumas maaser of demai which returned to its place, R’ Shimon Shezuri says: Even on a weekday, one may ask [the seller] and eat [the fruit based] on his word.

[If] one imposes a vow on his fellow that he should eat with him, and [his fellow] does not trust him regarding tithes, he may eat with him on the first Sabbath, even though he does not trust [the host] regarding tithes, provided that [the host] says to him: ‘‘[The food] is tithed.’’ But on the second Sabbath, even though [the host] vowed that [his fellow] not have ben-efit from him, he may not eat unless he separates the tithes.

R’ Eliezer says: One does not need to verbally designate maasar ani from demai. But the Sages say: One verbally designates [it], but he does not need to separate [it].