15 · חַלָּה א:ג · Challah 1:3
אֵלּוּ חַיָּבִין בַּחַלָּה וּפְטוּרִים מִן הַמַּעַשְׂרוֹת:
הַלֶּקֶט, וְהַשִּׁכְחָה, וְהַפֵּאָה, וְהַהֶפְקֵר,
וּמַעֲשֵׂר רִאשׁוֹן שֶׁנִּטְּלָה תְרוּמָתוֹ,
וּמַעֲשֵׂר שֵׁנִי וְהֶקְדֵּשׁ שֶׁנִּפְדּוּ,
וּמוֹתַר הָעֹמֶר,
וּתְבוּאָה שֶׁלֹּא הֵבִיאָה שְׁלִישׁ.
רַבִּי אֱלִיעֶזֶר אוֹמֵר, תְּבוּאָה שֶׁלֹּא הֵבִיאָה שְׁלִישׁ, פְּטוּרָה מִן הַחַלָּה.
The following are obligated in challah but exempt from tithes: gleanings, forgotten sheaf, pe'ah, ownerless produce, maaser rishon from which terumah was removed, maaser sheni and consecrated produce that were redeemed, the surplus of the Omer, and grain that has not yet reached one-third ripeness. R' Eliezer says: grain that has not reached one-third ripeness is also exempt from challah.