וְקָרַ֨ב אֹתָ֜ם אֶחָ֧ד אֶל־אֶחָ֛ד לְךָ֖ לְעֵ֣ץ אֶחָ֑ד וְהָי֥וּ לַאֲחָדִ֖ים בְּיָדֶֽךָ׃
און גענען זײ דיר אײנעם צום אַנדערן אין אײן האָלץ, אַז זײ זאָלן װערן אײנס אין דײַן האַנט.
Tze'enah Ure'enah
“Join together in one stick, etc.” [37:17]. First take two sticks and write a name on each one. This means that Israelites have been separated through the wars of their kings. Therefore, God said: take the two sticks and bring them together in one hand. This is a sign that the kingdom of Israel will have peace and will be united. When Israelites will say to you: tell us, what do these sticks show? You should tell them. Thus has God said: I take the stick on which Joseph is written, that is in the hand of Ephraim, and I will put it together with the stick of Judah. You should make them one stick and they will be united in my hand. You should hold the sticks on which you have written in your hand before their eyes.
Rashi
and they shall be one I shall join the two sticks, so that they will be one stick in your hand.