John Chrysostom
To aid in their remembrance of His blessings in various ways, God instructs His people, akin to children, to perform what many do to combat forgetfulness: they were to attach blue threads around the edges of their garments, extending to their feet. This custom served as a reminder of His commandments, and these threads were referred to as "wings." They made a point to create broad bands for these fringes and to widen the wings of their garments, revealing their excessive pride. Why do you take pride in expanding them (Matthew 23:5)? Does your righteousness lie in such displays? What benefit do they provide if you do not heed the reminders they offer? God asks not for their adornment to be increased, but for you to recall His blessings. If acts of charity and fasting, which demand effort and signify our good deeds, are not to be glorified, how then, O Jew, can you elevate yourself in matters that distinctly highlight your inattention?