(י) טַפְּכֶם נְשֵׁיכֶם וְגֵרְךָ אֲשֶׁר בְּקֶרֶב מַחֲנֶיךָ מֵחֹטֵב עֵצֶיךָ עַד שֹׁאֵב מֵימֶיךָ.
Who were these wood cutters and water drawers? Rashi says they were Canaanite converts to Judaism.
How did he know that?
When the Givonim heard of the great military strength of the Israelites, they dressed up as foreigners from a faraway land and attempted to make peace with the Israelites (God demanded that the Israelites never make peace with certain inhabitants of Israel at that time).
Yehoshua, without realizing, makes a covenant with the Givonim, which is was not supposed to do; he was supposed to kill them. But he made a brit (covenant), which cannot be broken, that he would never harm them. So what's a good compromise?
(כא) וַיֹּאמְרוּ אֲלֵיהֶם הַנְּשִׂיאִים יִחְיוּ וַיִּהְיוּ חֹטְבֵי עֵצִים וְשֹׁאֲבֵי מַיִם לְכָל הָעֵדָה כַּאֲשֶׁר דִּבְּרוּ לָהֶם הַנְּשִׂיאִים.
They become wood cutters and water drawers for the nation, which must have been a position of low status.
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