While the blind men could not actually ensure that no one knows about their healing, because of the obviousness of the healing itself, they were still sinning in disobeying Jesus’ command by spreading the news, which showed a lack of gratitude to Jesus.
There is a distinct irony here in that his command is impossible to be carried out. How could it be hidden from the public that these two men could now see again, especially after they had visited Jesus in his house. Even if they kept silent, the facts would speak for themselves.1
These two men, having been healed from their blindness, acted sinfully in spreading Jesus’ fame throughout the district, even if their actions are understandable. They simply could not resist telling everyone about their miraculous healing. Yet they were clearly disobedient. Here we learn that even in such difficult situations as this one, where the spread of the message itself was inevitable, humble obedience is better than impulsive spontaneity.2 The disobedience of the men is a testimony to their ungratefulness towards Jesus.3
30 And their eyes were opened. And Jesus sternly warned them, “See that no one knows about it.”