In the previous episode, the subtitler made a mistake. Walt didn't say 'Mr Locke said a miracle happened here.' He said, 'Mr Locke said a miracle happened to him.' And it did. He's on a journey of spiritual renewal after all.
John Locke was a 17th century philosopher who essentially pioneered the idea of individual rights - that there wasn't anything people should be told they can't do, in other words.