The phrase "whence came" is often used to indicate the origin or source of something. However, there are several synonyms that can be used instead of this phrase to add variety and depth to your writing. "Originated from" is a simple and straightforward alternative that retains the same meaning. "Derived from" is another option that emphasizes the process of something coming into existence. "Emerged from" is a more poetic phrase that suggests a gradual and perhaps mysterious origin. "Sprung from" is a similar option that lends a sense of energy and vitality to the description. Ultimately, the choice of synonym will depend on the particular context and tone of your writing.