(idiom) someone is hardly able to save herself/himself in a plight
Definitions (粵典–words.hk)
語句
歇後語嘅上半句，下半句係「自身難保」，就好似用泥造嘅菩薩像，會喺過江嗰陣，因為遇到水而冧晒，保唔住原先個樣 a "sandwich pun" meaning unable to protect one's own interests (let alone the interests of others); literally: clay buddha crosses the river