Mishnah Menachot 10:8: They may reap in irrigated fields in the valley [before the omer is brought], but they may not stack it. The people of Jericho used to reap [before the omer was brought in accordance] with the will of the Sages, and used to stack it against the will of the Sages, but the Sages did not protest. One may reap hay to feed livestock; Rabbi Judah said: When is this so? If one had begun to reap it before it had brought forth a third [of its growth]. Rabbi Shimon says: one may even reap it and feed [his livestock with it] even after it has brought forth a third [of its growth].

קוצרים בית השלחים שבעמקים, אבל לא גודשין. אנשי יריחו קוצרין ברצון חכמים, וגודשין שלא ברצון חכמים, ולא מחו בידם חכמים. קוצר לשחת, ומאכיל לבהמה. אמר רבי יהודה: אימתי, בזמן שהתחיל עד שלא הביאה שליש. רבי שמעון אומר: אף יקצור ויאכיל אף משהביאה שליש.

Mishnah Menachot 10:9: One may harvest for the sake of the saplings [i.e., to promote their growth], for the sake of a house of morning, and for the sake of a house of study, [but in such cases], one should not bind them but rather leave them in loose bunches. The [best fulfillment of the] commandment of the omer is that is come from standing grain; if he did not find any, he may bring from bundled grain. [The best fulfillment of] its commandment is that it come green; if he did not find any, he may bring it dry. [The best fulfillment of] its commandment is that it be reaped at night; if it was reaped during the day, it is still valid; and its [reaping] overrides Shabbat [prohibitions].

קוצרין מפני הנטיעות, מפני בית האבל, מפני [בטול] בית המדרש. לא יעשה אותן כריכות, אבל מניחן צבתים. מצות העמר לבוא מן הקמה. לא מצא, יביא מן העמרים. מצותו לבוא מן הלח. לא מצא, יביא מן היבש. מצותו לקצור בלילה. נקצר ביום, כשר. ודוחה את השבת .