Louw Nida points to Matthew 6:1, "Take heed that you do not do your
charitable deeds before men, to be seen by them."
But TDNT says the following...
If we ignore these passages, and postpone for the moment our consideration of the distinctive Pauline formula δικαιοσύνη θεοῦ, we may first maintain that δικαιοσύνη is almost always used in the NT for the right conduct of man which follows the will of God and is pleasing to Him, for rectitude of life before God, for uprightness before His judgment. The fact that the basic relationship to God is always in view, and that it is related to the event of revelation, distinguishes this usage from Greek and Hellenistic ethics and links it firmly with the OT. A brief review of the non-Pauline writings will confirm this.
Schrenk, G. (1964–). δίκη, δίκαιος, δικαιοσύνη, δικαιόω, δικαίωμα, δικαίωσις, δικαιοκρισία. In G. Kittel, G. W. Bromiley, & G. Friedrich (Eds.), Theological dictionary of the New Testament (electronic ed., Vol. 2, p. 198). Eerdmans.
My point is that "righteousness" does not always relate to "righteous deeds". In fact, I find that most of the time it relates to people holding up under the scrutiny of God's judgement (i.e., a person is righteous if God sees him as being right with Him). An example of this is Romans 4:5...
But to him who does not work but believes on Him who justifies the ungodly, his faith is accounted for righteousness (Ro 4:5).
Paraphrasing, it says, "But to him who is not working to gain right standing with God but believes on Him who declares ungodly people to be right with Him, God considers this person to be in right standing with Him on the basis of what he believes".
Certainly, "righteousness" in this verse can't be talking about "righteous deeds" because the ungodly person in this verse didn't pursue those.