Adam Clarke on Romans 14:3

Let not him that eateth - The Gentile, who eats flesh, despise him, the Jew, who eateth not flesh, but herbs. And let not him, the Jew, that eateth not indiscriminately, judge - condemn him, the Gentile, that eateth indiscriminately flesh or vegetables.

For God hath received him - Both being sincere and upright, and acting in the fear of God, are received as heirs of eternal life, without any difference on account of these religious scruples or prejudices.