Following are a number of back-translations of Romans 10:20:

• Uma: “After that, there is also the Word of God that is very clear, that was announced by the prophet Yesaya. God said like this: ‘The people who did not search for me, they are the ones who ended up finding me. And the people who did not ask who I was, I ended up telling them who I was.'” (Source: Uma Back Translation)
• Yakan: “Then Nabi Isaya was also not afraid to speak, he said, ‘This is what God said, ‘The ones who did not look for me, they are the ones who found me. The ones who did not ask about me, they are the ones to whom I show myself.’ ‘” (Source: Yakan Back Translation)
• Western Bukidnon Manobo: “And even more clean is the word of God which Isaiah was caused to preach long ago, for he said, ‘I was found by the people who were not looking for me, and even though that they were not asking about me, I caused them to understand who I was,’ he said.” (Source: Western Bukidnon Manobo Back Translation)
• Kankanaey: “What God caused-Isaias -to-write about the Gentiles is even clearer. He says, ‘Those who weren’t looking for me, they are the ones who found me. Those who inquired nothing about me, they are the ones to-whom-I-appeared.'” (Source: Kankanaey Back Translation)
• Tenango Otomi: “But Isaiah plainly said in what he wrote about the word God spoke, saying: ‘The people who did not seek me are the ones who found in their hearts (= understood) so as to know me. The people who did not ask about who I am, are the ones who met up with me’ said God.” (Source: Tenango Otomi Back Translation)
• Huehuetla Tepehua: “And the ancient servant of God who was called Isaiah really wasn’t afraid (to speak). This is what he said: This is what God says, Those who didn’t hunt for me, they are the ones who found me. And those who didn’t ask about me, they are the ones that I have shown myself to.” (Source: Waterhouse / Parrott in Notes on Translation October 1967, p. 1ff.)

For the Old Testament quote, see Isaiah 6:51.