Reference for Zevachim 64:1

סמיכה נמי כתיב לפני ה' אפשר דמעייל ידיה וסמיך שחיטה נמי אפשר דעביד סכין ארוכה ושחיט

but 'before the Lord' is written in connection with 'laying' too? - He can project his hands within and lay [them on the bullock]. Then in the case of shechitah too, he can make a long knife and slaughter? - This agrees with Simeon the Temanite.

Jastrow