danforth does not want hale in the jail because

Danforth threatens to put Rev. Hale in jail because Hale has been counseling people to lie and say there were in council with the Devil to save themselves. The court tends shows mercy on people who renounce their sins rather than plead innocence. In the end Danforth really can't put Hale in jail because it would destroy the credibility of his court, his job and his own reputation.