ציטירנדיקער פּירוש אויף דברים 26:14

ואסורין לעונן – Regarding the [Second] tithe, it is written (Deuteronomy 26:14): “I have not eaten of iot while in mourning,” and regarding First Fruits, it is states (Deuteronomy 26:11): “And you shall rejoice, [together with the Levite and the stranger in your midst]…” which teaches that these are forbidden to someone in mourning (literally, someone whose dead lies before them, as yet unburied).

ומעשר שני שלא נפדה – Second Tithe that became defiled and even if he is in Jerusalem, it is prohibited to eat it until it is redeemed, but a person who eats it in Jerusalem while it is not yet redeemed, is flogged. And its explicit prohibition is from (Deuteronomy 26:14): “I have not cleared out any of it while impure,” whether I am defiled and it is ritually pure, whether I am ritually pure and it is ritually impure. And from where do we learn that Second Tithe which was defiled – that we redeem it in Jerusalem? As it states (Deuteronomy 14:24): “…should you be unable to transport them,” is explained as you are unable to eat it, as it is written (Genesis 43:34): “Portions were served them from the table…”

for their bread is for themselves It is fit for them for food, but not to come into the house of the Lord. Another explanation is: אוֹנִים, like bread of mourners, which is contaminated, and the end of the verse proves it: all those who partake thereof become contaminated.