Here Lewis refers to Mark 5:24-34 (cf. Luke 8:43-48) (KJV), one of many miracles of healing performed by Christ:
And Jesus, immediately knowing in himself that virtue had gone out of him, turned him about in the press, and said, Who touched my clothes?
And his disciples said unto him, Thou seest the multitude thronging thee, and sayest thou, Who touched me?
And he looked round about to see her that had done this thing. But the woman fearing and trembling, knowing what was done in her, came and fell down before him, and told him all the truth. And he said unto her, Daughter, thy faith hath made thee whole; go in peace, and be whole of thy plague.