Luke 1:51

He hath shewed strength with his arm; he hath scattered the proud in the imagination of their hearts.

With His arm means God actively exercises His own power to scatter the proud. The proud so scattered are those whose inner life is fixed on their own ideas and on the schemes devised in their hearts. That scattering overturns human self-exaltation and expresses God's just regard for the humble. The declaration belongs together with the surrounding assurance that He shows mercy to those who fear Him and that He lifts up the lowly while bringing down the mighty.