The child's misery would move even the most obdurate heart.
Stubbornly adhering to an attitude, an opinion, or a course of action; obdurate.
Scrooge, the obdurate miser in a Christmas Carol, is finally moved by the Christmas spirit to ACTS of charity.
A few weeks ago, I spoke to someone who had finally reached the end of her rope with an obdurate boss.
Where the initial memories of the city, even in the face of resolve in time, it is always the most obdurate attitude.
And for a contrary reason, how disagreeable does he appear to be, whose hard and obdurate heart feels for himself only, but is altogether insensible to the happiness or misery of others!