The good nuns, who had been so sure of her vocation, perceived with great astonishment that Mademoiselle Rouault seemed to be slipping from them. They had indeed been so lavish to her of prayers, retreats, novenas, and sermons, they had so often preached the respect due to saints and martyrs, and given so much good advice as to the modesty of the body and the salvation of her soul, that she did as tightly reined horses; she pulled up short and the bit slipped from her teeth.
Source: wiktionary