What does Ezekiel 37:13 mean?

So I prophesied as he commanded me, and the breath came into them, and they lived, and stood up on their feet, an exceedingly great army.

Then he said to me, “Son of man, these bones are the whole house of Israel. Behold, they say, ‘Our bones are dried up, and our hope is lost. We are completely cut off.’

Therefore prophesy, and tell them, ‘Thus says the Lord Yahweh: “Behold, I will open your graves, and cause you to come up out of your graves, my people; and I will bring you into the land of Israel.

I will put my Spirit in you, and you will live. Then I will place you in your own land; and you will know that I, Yahweh, have spoken it and performed it,” says Yahweh.’”

Yahweh’s word came again to me, saying,

“You, son of man, take one stick, and write on it, ‘For Judah, and for the children of Israel his companions.’ Then take another stick, and write on it, ‘For Joseph, the stick of Ephraim, and for all the house of Israel his companions.’