Heb 12:13

“Here he speaks as if to runners, as he also said above: "let us run with patience." So he says: "make straight paths for your feet." A "path" is either the track of a running chariot imprinted on the ground (a rut), or the place beneath the feet of those who run. So he says, let your paths, or your ways, be easy and level, that is, let there be nothing rough and sorrowful and uneven in your souls, but walk straight, without grief and easily, lest the lame, that is, those who by nature are disposed to excessive faintheartedness, like the Jews, for such is that people, or those who are lame with respect to faith in what is to come, be compelled to go astray, and through this your feet be turned aside from the path, that is, lest you become utterly wicked. For one who is overcome by natural or initially accidental faintheartedness, not strengthening himself but yielding to it more and more, imperceptibly reaches the utmost degree of despair, so that from that point it becomes difficult to restrain him. But make every effort that your lameness be healed quickly, that is, if you still have any unbelief up to now, correct yourselves quickly. For is there any place for unbelief in the patient person? See how he openly introduces the idea of repentance, and note that this is directed against the Novatians.”

“685. – Then (v. 13) he rebukes the sin of transgression. Now that sin is a kind of obliqueness and curvature. For that is straight whose middle does not point to a direction different from the extremes, i.e., whose action does not depart from its proper intention and end. But there are three kinds of obliqueness: namely in the affections, in action and in understanding. From sinful affection follows obliqueness in the understanding and depravity in loving. Therefore, in regard to the first, which is the root of the others he says, make straight paths for your feet, i.e., correct affections. For as the feet carry the body, so the affections carry the mind. Therefore, straight feet are proper affections: 'Their feet were straight feet' (Ez. 1:7). Therefore, make straight the affections, by which the whole body is carried spiritually. 'Make straight in the wilderness the paths of our Lord' (Is. 40:3) i.e., as far as in you lies, devote yourself to this. In regard to the second, he says, so that what is lame as to outward action. For just as the tibia is said to be lame, when it does not follow the rule of the locomotive power, so an action is lame when it turns to the right in prosperity or to the left in adversity, and does not follow the rule of divine law: 'This is the way: walk in it and do not go aside to the right or left' (Is. 30:21). Or he limps who along with the Gospel observes the ceremonial laws of the Old Testament. In regard to obliqueness of the understanding he says, may not be put out of joint. For an intellectual error follows an evil action: 'They err that do evil' (Pr. 14:22); 'These things they thought and were deceived; for their own malice blinded them' (Wis. 2:21). Therefore, a person who would avoid those two deviations must have his feet and his affects right; hence, he says, but rather be healed. For just as bodily health consists in the proper balance of the humors, so spiritual health in the proper arrangement of the affections: 'Heal me, O Lord, and I shall be healed' (Jer. 17:14).”

“Quoted from Pro 4:26, Septuagint, "Make straight paths for thy feet." straight--that is, leading by a straight road to joy and grace (Heb 12:1-2, Heb 12:15). Cease to "halt" between Judaism and Christianity [BENGEL]. paths--literally, "wheel tracks." Let your walk be so firm and so unanimous in the right direction that a plain track and "highway" may be thereby established for those who accompany and follow you, to perceive and walk in (Isa 35:8) [ALFORD]. that which is lame--those "weak in the faith" (Rom 14:1), having still Judaizing prejudices. be turned out of the way-- (Pro 4:27); and, so missing the way, lose the prize of "the race" (Heb 12:1). rather he healed--Proper exercise of itself contributes to health; the habit of walking straight onward in the right way tends to healing.”