Or HaChaim on Numbers 15:30/אור החיים על במדבר ט״ו:ל׳

1 והנפש אשר תעשה ביד רמה, But the person who acts defiantly, etc. This means that if someone deliberately worships idols, G'd considers it as if he had blasphemed against Him. This is why his punishment is that he will be cut off from amongst his people.

2The Torah adds: כי דבר ה׳ בזה, "for he has despised the word of G'd." This means that inasmuch as the sin of idolatry is equivalent to rejection of the entire Torah, such a person has despised every word of G'd. The Torah adds that ואת מצותו הפר, "and he has violated His commandment," i.e. by worshiping idols he has in effect violated all the negative commandments. As a result, הכרת תכרת הנפש ההיא. The word הכרת refers to the tendons of the soul, the word תכרת to the limbs of the soul. The soul is perceived as being made up of parallel parts to those of the body. Just as the body consists of 365 tendons and 248 limbs, so is the soul a composite of 613 parts. Once a person is treated as if he had violated all the 613 commandments no vestige of his soul remains. Such a soul can never be repaired. This is the deeper meaning of the words עונה בה, "its sin remains an ongoing fact." Our sages in Sanhedrin 90 explain this differently. We know that the written Torah can be explained in many different ways.