Our Gemara on Amud Aleph states: Kol (all) mitzvot performed by Jews in this world will testify for them in the World-to-Come, per Yeshayahu: “Let them bring their witnesses…” Commentaries emphasize kol to include various mitzvos :

• Ben Yehoyada: Rabbinic mitzvos and hiddur mitzvah (e.g., a beautiful Esrog or neat mezuzah).
  
• Pesach Eynaim: Mitzvos that others performed inspired by one’s influence.
  
• Maris Ayin: Mitzvos of abstention (resisting prohibitions when tempted).

These views align: mar amar chada, umar amar chadavelo peligi—each highlights a facet without contradiction. Kol stresses that intention, effort, and purity amplify impact.

Why do we need a verse? Doesn’t Tehillim (33:15) state: “He who formed the hearts… comprehends all…” This implies that God values intent. However, I believe that This teaching isn’t about reward or punishment but the effects of mitzvos. Commentaries describe mitzvos creating angels or forces, shaping us and the world, like witnesses enabling outcomes (e.g., Reuven owing Shimon). Similarly, a man may diet for his health to reduce his cholesterol and high blood pressure, but gains confidence, and improving other aspects of his life. So too mitzvos yield side benefits, the agents mal’ach (messenger) beyond reward, per God’s plan.

One might assume only technical fulfillment triggers benefits, like qualifying for a community perk. The Gemara teaches that effort, mindset, and enhancements proportionately amplify positive ripples on personality and community, the true testimony of mitzvos.