Matthew Poole and continuators on Hebrews 13:9

9 Be not carried about with divers and strange doctrines: For it is a good thing that the heart be established with grace, not with meats, which have not profited them that have been occupied therein.

The Doctrine of Christ being immutable, it is but necessary to dehort his Subjects from deserting it, which the Apostle doth here; that they should not be wheeling or whirling about with an unstable and inconstant motion of Judgment, Faith and Practice about such Humane Doctrines, which are vain Rules to lead to God, such as are different in Nature from Christ, one and the same Rule, and those very numerous and various, strange and untrue, taught by false Apostles and Teachers, taken out of Gentilism and Iudaism, and added to the Gospel by them, as necessary, together with Christ to Justification and Salvation, Matth. 15.9. 2 Cor. 11.3. Ephes. 4.14. 2 Thess. 2.10, 12. 1 Tim. 4.1, 2, 3. 2 Tim. 4.3, 4. 2 Pet. 2.1, 18, 19. Iude v. 12.

For the goodness of heart-establishment unto God, is no less than full and compleat Salvation of the Soul, 1 Cor. 15.58. 2 Pet. 3.17, 18. And this is only wrought by Grace, the free love of God put out in Christ, for regeneration and preservation of Souls unto Life Eternal, carried in the simple Doctrine of Christ, which is always the same, 2 Thess. 2.16, 17. and 1 Pet. 5.10.

Doctrines of Meats and Ceremonies, which are divers, and strange from Christ's, cannot make the Heart agreeable to God, but only distract and divide it from him, for whatsoever is not in and from Christ, is strange to God, and abhorred by him, Gal. 5.2. Col. 2.18, 19, 23. 2 Tim. 2.16. Iames 1.8.

Those who did converse in these various and strange Doctrines, professing and constantly practising them, observed Times and Meats, and Ceremonies, have not been profited by them, for being carnal and earthly, they could not justify them as to their state God-ward, nor could they renew or sanctify their Souls, nor yield any advantage to their Spiritual Life, and being perishing, could not profit to the attaining of Eternal Life, Rom. 14.17, 18. compare 1 Cor. 6.13.

Marginal references: Eph. 5.6. 1 John 4.1.; Rom. 14.17.