Thomas Aquinas, on Heb 13:9

“Be not led away with various and strange doctrines. For it is best that the heart be established with grace, not with meats; which have not profited those that walk in them.”

“After exhorting them to follow the example and manner of life of those who have departed, the Apostle now warns them to continue in their teaching. In regard to this he does two things: first, he gives the warning; secondly, the reason (v. 10). In regard to the first he does two things: first, he warns them in general; secondly, he explains the warning (v. 9b). He says, therefore: Do not be led away by diverse and strange teachings. As if to say: Thus we have said that you should imitate the faith of the apostles. Therefore, do not be led away from their teaching to any other doctrine. Here it should be noted that since truth consists in the mean, which is one, many false statements can be opposed to one truth, just as there are many extremes to one middle. Therefore, the doctrine of faith is one, because only one line can be drawn between two points. But all other doctrines are manifold, because there are many deviations from what is straight. Hence, he says, by diverse doctrines, i.e., divided: 'Their heart is divided: now they shall perish' (Hos 10:2). These are the doctrines about which he said (1 Tim. 4:1): 'Doctrines of devils, speaking lies in hypocrisy.' Furthermore, they are strange, i.e., straying from the Catholic faith. But such doctrines must not be supported by us, because 'we are not strangers and foreigners, but fellow citizens of the saints, and the domestics of God' (Eph. 2:19). Then when he says, For it is well that the heart be strengthened by grace, he explains in detail which are various and strange doctrines. Here it should be noted that in the early Church there was one error rampant, namely, that it was necessary for salvation to observe the ceremonies of the Law, which consisted especially in partaking of certain foods, such as the paschal lamb (Ex. 12) and in abstaining from certain foods, as is clear from Leviticus (chap. 12) and from other passages. Another error was that of the Nicolaitans, that it was lawful to use bodily pleasures indiscriminately. These words can be applied to both these errors, but more properly to the first. He says, therefore, Be not led away from the truth by diverse and strange doctrines: 'Be not easily moved from your sense' (2 Th. 2:2); 'I wonder that you are so soon removed from him that called you into the grace of Christ, unto another gospel' (Gal. 1:6). For God requires our heart of us: 'My son, give me your heart' (Pr. 23:26); therefore, it is well that the heart be strengthened with grace. For it should be firm and stable; against which Ps. 39 (v. 13) says: 'My heart has forsaken me.' But it is not strengthened with bodily foods, but with sanctifying grace: 'Justified freely by his grace' (Rom. 3:24) and with the redemption which is in Christ Jesus. Therefore, he says, not by foods, which have not benefited their adherents: 'The kingdom of God is not meat and drink, but justice and peace and joy in the Holy Spirit' (Rom. 14:17). Therefore, the heart is not established with moderate or superfluous use of food, but rather with God's grace: 'His heart is ready to hope in the Lord, his heart is strengthened he shall not be moved until he look over his enemies' (Ps. 111:8). But hope is an anchor stabilizing the heart: 'We have fled for refuge to hold fast the hope set before us, which we have as an anchor of the soul, sure and firm' (Heb. 6:18). And he says, which have not benefited their adherents, i.e., hope in them, because those who use them for bodily needs profit with bodily health, but those who put their entire interest in them, walk in them. These are the ones whom they do not profit unto the salvation either of soul or body: 'Shall the holy flesh take away from you your crimes, in which you have boasted?' (Jer. 11:15).”

Imported from an open dataset — not yet checked against the printed edition.