Parashas Vayikra · Aliyah 1 · Passuk 4
Chabad.org — English translation + Rashi
Torah Temima points to Zevachim 119b.
E-Daf / Tsurras Hadaf (size=3 where available)
PDF of the daf / source
English: S’michah is not practiced on a private altar (bamah), because the verse links “he shall bring it before the Lord” with “and he shall lean.”
Restriction of the mitzvah of semichah to the official sanctuary — it is not performed on a private altar or outside the Temple precincts.
The personal act of leaning is bound to the presence of the Shechinah in the designated place of the Mishkan or Mikdash, teaching that certain expressions of closeness require the proper setting of communal holiness.