Albert Barnes Commentary Romans 14:6

"He that regardeth the day, regardeth it unto the Lord: and he that eateth, eateth unto the Lord, for he giveth God thanks; and he that eateth not, unto the Lord he eateth not, and giveth God thanks." — Romans 14:6 (ASV)

He that regardeth. Greek, Thinks of; or pays attention to; that is, he who observes it as a festival, or as holy time.

The day. Any of the days under discussion; the days that the Jews kept as religious occasions.

Regardeth it unto the Lord. He regards it as holy, or as set apart to the service of God. He believes that he is required by God to keep it, that is, that the laws of Moses in regard to such days are binding on him.

He that regardeth not the day. Or who does not observe such distinctions of days as are demanded in the laws of Moses.

To the Lord he does not regard it. That is, he does not believe that God requires such an observance.

He that eateth. The Gentile Christian, who freely eats all kinds of meat (Romans 14:2).

Eateth to the Lord. He eats to the Lord because he believes that God does not forbid it, and because he desires, in doing it, to glorify God (1 Corinthians 10:31). To eat to the Lord, in this case, is to do it believing that such is his will.

In all other cases, it is to do it feeling that we receive our food from him, rendering thanks for his goodness, and desiring to be strengthened that we may do his commands.

He giveth God thanks. This is an incidental proof that it is our duty to give God thanks at our meals for our food. It shows that it was the practice of the early Christians and has the commendation of the apostle. It was also uniformly done by the Jews and by the Lord Jesus (Matthew 14:19; Matthew 26:26; Mark 6:41; Mark 14:22; Luke 9:16; Luke 24:30).

To the Lord he eateth not. He abstains from eating because he believes that God requires him to do it, and with a desire to obey and honour him.

And giveth God thanks. That is, the Jew thanked God for the law, and for the favour he had bestowed on him by giving him more light than the Gentiles had. For this privilege they valued themselves highly, and this feeling, no doubt, the converted Jews would continue to retain, deeming themselves as specially favoured in having a peculiar acquaintance with the law of God.