Following are a number of back-translations as well as a sample translation for translators of Exodus 4:21:

• Kupsabiny: “God told Moses while on the journey that, ‘When you reach Egypt, do the things I have shown you before the ruler/king. But I will make the head of the ruler/king to be hard/dry (unresponsive) so that he may not release the people of Israel to go.” (Source: Kupsabiny Back Translation)
• Newari: “God said to Moses," Having gone back to Egypt, by means of the power that I have given you perform before Pharaoh showing all the miracles. But I will harden his heart; he will refuse to let the people go.” (Source: Newari Back Translation)
• Hiligaynon: “The LORD said to Moises, ‘When- you (sing.) -arrive in Egipto, perform/do before/[lit. in front-of] the king all the miracles that I have-shown to you (sing.). I have-given you (sing.) power to do those. But I will-harden/[lit. make-hard] the heart of the king so-that he will- not -allow the Israelinhon to leave.” (Source: Hiligaynon Back Translation)
• Bariai: “And then the Chief spoke to Moses like this, ‘When you arrive in Isip, you must cause those miracles to come about in the sight of the great chief. Those miracles, I empowered you to do them. But I will make so that the great chief is unwavering (lit. has a hard interior) and refuses to listen (lit. shuts his ears), and so he certainly won’t allow my people to go.” (Source: Bariai Back Translation)
• Opo: “And The Lord said to Moses «When you will return Egypt, sign which I gave you power that you might do, you do it in front of king of Egypt. But, I will make his heart that it might be hard, in order that he might not people release.” (Source: Opo Back Translation)
• English: “Yahweh said to Moses/me, ‘When you return to Egypt, be sure to perform all the miracles that I have given you power to do, while the king is watching. But I will make him stubborn , with the result that he will not let the Israeli people leave Egypt.” (Source: Translation for Translators)