TT #43 · Parashas Reeh · First Aliyah · Passuk 12:08
You shall not do according to all that we do here today, every man whatever is right in his own eyes.
Torah Temimah points to Sifrei / Zevachim.
English: “That we do here today” — This teaches that until the Mishkan was erected the private altars (bamot) were permitted. And what did they offer? An individual offered voluntary offerings and the community offered obligatory offerings, as the verse says “you shall not do according to all that we do here today, every man whatever is right in his own eyes” — an individual [offers] voluntary ones, and the community even obligatory ones.
Derash on the verse (Sifrei) — the status of bamot before the Mishkan and the types of offerings allowed.
Before the Mishkan was erected, bamot were permitted; individuals could offer voluntary sacrifices and the community could offer obligatory ones.