Exodus 29:42

This shall be a continual burnt offering throughout your
generations
To be offered up morning and evening in every age, as long as the Mosaic economy lasted, till he came, who put an end to it by offering up himself, the antitype of it:

at the door of the tabernacle of the congregation before the Lord;
that is, upon the altar of burnt offering which stood there, see ( Exodus 40:29 ) :

where I will meet you to speak there unto thee;
to accept of their sacrifices, give further directions of what was to be done, and answers to inquiries made of him in matters of moment and difficulty. Jarchi observes, that some of their Rabbins conclude from hence, that the holy blessed God spoke with Moses from off the altar of brass, after the tabernacle was set up; but others say from off the mercy seat, as in ( Exodus 25:22 ) .