Romans 8:26

The apostle here suggests two privileges more to which true Christians are entitled: - I. The help of the Spirit in prayer. While we are in this world, hoping and waiting for what we see not, we must be praying. Hope supposes desire, and that desire offered up to God is prayer; we groan. Now observe, 1. Our weakness in prayer: We know not what we should pray for as we ought. (1.) As to the matter of our requests, we know not what to ask. We are not competent judges of our own condition. Who knows what is good for a man in this life? Ecc 6:12. We are short-sighted, and very much biassed in favour of the flesh, and apt to separate the end from the way. You know not what you ask, Mat 20:22. We are like foolish children, that are ready to cry for fruit before it is ripe and fit for them; see Luk 9:54, Luk 9:55. (2.) As to the manner, we know not how to pray as we ought. It is not enough that we do that which is good, but we must do it well, seek in a due order; and here we are often at a loss - graces are weak, affections cold, thoughts wandering, and it is not always easy to find the heart to pray, Sa2 7:27. The apostle speaks of this in the first person: We know not. He puts himself among the rest.

— Matthew Henry's Concise Commentary (public domain)

Likewise the Spirit also, &c.--or, "But after the like manner doth the Spirit also help. our infirmities--rather (according to the true reading), "our infirmity"; not merely the one infirmity here specified, but the general weakness of the spiritual life in its present state, of which one example is here given. for we know not what we should pray for as we ought--It is not the proper matter of prayer that believers are at so much loss about, for the fullest directions are given them on this head: but to ask for the right things "as they ought" is the difficulty. This arises partly from the dimness of our spiritual vision in the present veiled state, while we have to "walk by faith, not by sight" (see on Co1 13:9 and Co2 5:7), and the large admixture of the ideas and feelings which spring from the fleeting objects of sense that there is in the very best views and affections of our renewed nature; partly also from the necessary imperfection of all human language as a vehicle for expressing the subtle spiritual feelings of the heart.

— Jamieson-Fausset-Brown Commentary (public domain)