Jerusalem Talmud Yevamot 4:14

משנה: וְאֵי זֶהוּ מַמְזֵר כָּל־שְׁאֵר בָּשָׂר שֶׁהוּא בְלֹא יָבוֹא דִּבְרֵי רִבִּי עֲקִיבָא. שִׁמְעוֹן הַתִּימְנִי אוֹמֵר כָּל־שֶׁחַייָבִים עָלָיו כָּרֵת בִּידֵי שָׁמַיִם וַהֲלָכָה כִדְבָרָיו. רִבִּי יְהוֹשֻׁעַ אוֹמֵר כָּל־שֶׁחַייָבִים עָלָיו מִיתַת בֵּית דִּין. MISHNAH: And what is a bastard? Any [child of a] blood-relation to whom he is forbidden to come, the words of Rebbi Aqiba. Simeon from Timna²⁰⁸One of the youngest members of the Academy at Jabne. says, any [child of a relation] for which one is subject to extirpation by heaven’s action²⁰⁹As detailed in Lev. 20, also including capital crimes., and practice follows him. Rebbi Joshua said, any [child of a relation] which is a capital crime.