Following are a number of back-translations of Mark 8:16:

• Uma: “But they did not know the meaning of that riddle, so they began talking among themselves, they said: ‘The reason he said that is that we don’t have any bread.'” (Source: Uma Back Translation)
• Yakan: “His disciples spoke-among-themselves about what he had said because they did not understand it. They said, ‘Perhaps that’s why he speaks like that, because we (incl.) didn’t take bread along.'” (Source: Yakan Back Translation)
• Western Bukidnon Manobo: “They didn’t understand that it wasn’t really for bread he was talking about. So they were talking together, they said, ‘The reason he says this is because we did not bring our supply of bread.'” (Source: Western Bukidnon Manobo Back Translation)
• Kankanaey: “When he told them that, they talked-together saying, ‘Jesus said that because we have no bread for our pack-lunch.'” (Source: Kankanaey Back Translation)
• Tagbanwa: “When those disciples heard, they said-among-themselves, ‘He spoke like that because we don’t have any bread with us.'” (Source: Tagbanwa Back Translation)
• Usila Chinantec: “They asked each other why he had said this, and finally decided that it was because they had no bread.”
• Michoacán Nahuatl: “Then they began to say to each other, He said this because we didn’t bring bread. They spoke thus because they did not know that Jesus was talking about the teaching of the Pharisees and of Herod.”
• Tzotzil: “There they began to say among themselves, In all probability it is because he knows that we have not brought bread. The disciples said this among themselves because they did not realize what the yeast was that Jesus talked about, that it is like the teachings of the Pharisees and of Herod.” (Source for this and two above: B. Moore / G. Turner in Notes on Translation 1967, p. 1ff.)