20 Adar (Vayakhel-Pekudei)

The Rashba"m on Pesachim 112a says that we see that a person should knock before going into their own house from the fact that the Kohen Gadol had bells on the Ephod always informing where he was ("vinishma kolo beva'o el hakodesh"/ its sound should be heard when he goes into the kodesh). But the Kohen Gadol was entering Hashem's house. How can we learn from there that we must knock before we go into our own house?