1st Corinthians chapter 10, starting at verse 17 for context:
17 For we being many are one bread, and one body: for we are all partakers of that one bread.
18 Behold Israel after the flesh: are not they which eat of the sacrifices partakers of the altar?
If you eat of the sacrifices offered on an altar, then you are
partakers of that altar. The Jews did it in Jerusalem, and pagans did it too. People who ate food sacrificed on altars were
partakers of those altars.
19 What say I then? that the idol is any thing, or that which is offered in sacrifice to idols is any thing?
20 But I say, that the things which the Gentiles sacrifice, they sacrifice to devils, and not to God: and I would not that ye should have fellowship with devils.
21 Ye cannot drink the cup of the Lord, and the cup of devils: ye cannot be partakers of the Lord's table, and of the table of devils.
The perpetual sacrifice of the Eucharist is offered on the Lord's table, which is an altar.
I am not guilty of 'taking from' Sacred Scripture, not I.