The phrase "hast change heart" refers to a sudden change of mind or attitude. Its antonyms, on the other hand, are words that express a sense of stability, steadfastness, and consistency. Some antonyms for "hast change heart" could be phrases like "firm resolve", "steady determination", "unwavering conviction", or "unyielding loyalty". These antonyms imply a sense of permanence and consistency in one's beliefs, actions, and decisions. Instead of being fickle or prone to abrupt changes, they suggest a sense of groundedness and commitment to one's values and principles. By embodying these qualities, one can maintain a sense of inner strength and purpose.