(18) And the LORD answered Moses, “Single out Joshua son of Nun, an inspired man, and lay your hand upon him. (19) Have him stand before Eleazar the priest and before the whole community, and commission him in their sight. (20) Invest him with some of your authority, so that the whole Israelite community may obey.
וְסָמַכְתָּ אֶת יָדְךָ עָלָיו, כְּמַדְלִיק נֵר מִנֵּר. (במדבר כז, כ): וְנָתַתָּה מֵהוֹדְךָ, כִּמְעָרֶה מִכְּלִי לִכְלִי. וּ
"And place your hand on him", it's like a candle lighting one from another. "And invest him with your authority", like pouring from one vessel to the next.