Chulin11: 1
רֵאשִׁית הַגֵּז נוֹהֵג בָּאָרֶץ וּבְחוּצָה לָאָרֶץ, בִּפְנֵי הַבַּיִת וְשֶׁלֹּא בִפְנֵי הַבַּיִת, בְּחֻלִּין אֲבָל לֹא בְמֻקְדָּשִׁין. חֹמֶר בַּזְּרוֹעַ וּבַלְּחָיַיִם וּבַקֵּבָה מֵרֵאשִׁית הַגֵּז, שֶׁהַזְּרוֹעַ וְהַלְּחָיַיִם וְהַקֵּבָה נוֹהֲגִים בְּבָקָר וּבְצֹאן, בִּמְרֻבֶּה וּבְמוּעָט, וְרֵאשִׁית הַגֵּז אֵינוֹ נוֹהֵג אֶלָּא בִרְחֵלוֹת, וְאֵינוֹ נוֹהֵג אֶלָּא בִמְרֻבֶּה.
The [mitzvah of giving the] first of the fleece applies [both] in the Land and outside the Land, when the Temple exists and when the Temple does not exist, to unconsecrated animals but not to consecrated ones. The stringency of the [law of the] foreleg, the jaws, and the maw over the [law of the] first of the fleece is that the [law of the] foreleg, the jaws, and maw applies to cattle and to flocks, to many and to few, whereas the [law of the] first of the fleece applies only to sheep, and it applies only to many.