Sword of Destiny

Used by Julian Lethbury in “The Mission of Jane” when he was expecting Jane´s engagement to be broken because of her behavior and could refer to Sword of Damocles.

According to the legend, when Damocles spoke in extravagant terms of his sovereign’s happiness, Dionysius invited him to a sumptuous banquet and seated him beneath a naked sword that was suspended from the ceiling by a single thread. Thus, did the tyrant demonstrate that the fortunes of men who hold power are as precarious as the predicament in which he had placed his guest. The story is related in Cicero’s Tusculanae disputationes (“Conversations at Tusculum”), Book V[1].

Used in speech, the figure of speech means someone is "in a situation in which something very bad could happen to them at any time". [2]

The usage of the figures of speech, like “Sword of destiny” or “Hand of God” highlights the situation of Mr. Lethbury´s character, who, even being a man and has more freedom than the female characters of Edith Wharton fiction, is caught in the external circumstances of being the adoptive father with an aim to marry his daughter off the hands.

[1] Source

[2] Source