Chulin2: 8
הַשּׁוֹחֵט לְשֵׁם הָרִים, לְשֵׁם גְּבָעוֹת, לְשֵׁם יַמִּים, לְשֵׁם נְהָרוֹת, לְשֵׁם מִדְבָּרוֹת, שְׁחִיטָתוֹ פְסוּלָה. שְׁנַיִם אוֹחֲזִין בְּסַכִּין וְשׁוֹחֲטִין, אֶחָד לְשֵׁם אֶחָד מִכָּל־אֵלּוּ, וְאֶחָד לְשֵׁם דָּבָר כָּשֵׁר, שְׁחִיטָתָן פְּסוּלָה.
[If] one slaughters as a sacrifice to [lit., in the name of] mountains, as a sacrifice to hills, as a sacrifice to seas, as a sacrifice to rivers, as a sacrifice to deserts, his slaughtering is invalid. [If] two hold a knife and slaughter, one [slaughters] as a sacrifice to one of these things, and one [slaughters] for a legitimate purpose, their slaughtering is invalid.