Why is the Jewish people compared to a vine?

Question: The Ben Ish Chai explains that the Jewish people is compared to a vine. What is special about the vine in particular?

Answer:

The vine is a weak and delicate plant, yet it produces excellent fruit that can be enjoyed as food and drink.

So too the Jewish people: although they sometimes look weak from the outside, their true strength lies in the spiritual fruit they produce: Torah study and the fulfillment of the mitzvot.

The Ben Ish Chai adds that no other tree can be grafted onto a vine. He sees this as a hint to the uniqueness of the Jewish people, about whom it is said:

“Behold, a people that shall dwell alone” (Numbers 23:9).

According to him, even a Jew who has drifted very far from holiness is never lost. In the end his soul will reach its rectification, because the Holy One, blessed be He, makes sure that no soul is cast away from Him.