The phrase "hast stab" doesn't seem to have any commonly used synonyms. It's a specific phrase that refers to a quick, sudden movement or attack with a pointed object, such as a knife or sword. However, there are many synonyms for the individual words "hast" and "stab". Synonyms for "hast" could include "rush", "hurry", "zoom", or "race". Synonyms for "stab" could include "thrust", "poke", "jab", or "pierce". While there may not be a specific phrase that directly matches "hast stab", there are many other ways to describe a swift, pointed attack.