הלכה על ביכורים 2:2

That He prohibited us from eating second tithe when grieving - even in Jerusalem - until it has been redeemed. And that is His saying, "I did not eat of it when grieving" (Deuteronomy 26:14). And the language of the Mishnah in Bikkurim (Bikkurim 2:2) is, "That the [second] tithe and firstfruits require being brought to [the appointed] place; they require confession; and they are forbidden to one grieving." And likewise anyone grieving is forbidden with regards to all consecrated foods due to this verse, as well as due to it being written in the Torah, "and such things have befallen me" (Leviticus 10:19). And the regulations of this commandment - meaning to say, grieving - have already been explained in the eighth [chapter] of Pesachim and the second [chapter] of Zevachim. And one who eats second tithe or tithes while grieving is lashed. (See Parashat Ki Tavo; Mishneh Torah, Second Tithes and Fourth Year's Fruit 3.)