Why does hazel call the river a test in watership down?

In "Watership Down," Hazel refers to the river as a test to illustrate the challenges and dangers the rabbits face in their journey. The river represents both a physical barrier and a metaphorical trial that tests their courage, teamwork, and survival instincts. Successfully navigating it reveals their resilience and ability to adapt, ultimately strengthening their bond as a community. This moment emphasizes the themes of perseverance and the necessity of overcoming obstacles in their quest for a safe home.