'Preparing' in the Bible

“As for you, son of man, thus says the Lord God, ‘Say to every kind of bird and to every animal of the field, “Assemble and come, gather from every side to My sacrifice that I am slaughtering for you, as a great sacrificial feast on the mountains of Israel, and you will eat flesh and drink blood.

So you will eat fat until you are filled and drink blood till you are drunk, at the sacrificial feast which I have prepared for you.