כִּי֩ יְדַבֵּ֨ר אֲלֵכֶ֤ם פַּרְעֹה֙ לֵאמֹ֔ר תְּנ֥וּ לָכֶ֖ם מוֹפֵ֑ת וְאָמַרְתָּ֣ אֶֽל־אַהֲרֹ֗ן קַ֧ח אֶֽת־מַטְּךָ֛ וְהַשְׁלֵ֥ךְ לִפְנֵֽי־פַרְעֹ֖ה יְהִ֥י לְתַנִּֽין׃
’When Pharaoh shall speak unto you, saying: Show a wonder for you; then thou shalt say unto Aaron: Take thy rod, and cast it down before Pharaoh, that it become a serpent.’
Exodus
Adonoy said to Moshe, “On your way back to Egypt, see [keep in mind] all the wondrous [signs] that I have placed in your hand, and do them before Pharaoh. I will harden his heart, and he will not send the people out.