Who was the disciple who felt restless without his Guru and gazed at his face day and night?

The disciple who tells the story of Faith and Patience in Chapter 19 describes his own profound devotion in these terms. He explains that he would lovingly gaze at his Guru's face day and night, to the point where he felt neither hunger nor thirst. He states that his mind was restless without the Guru, who was his only constant contemplation and goal. This intense focus on the Guru was all that was expected of him, and in return, the Guru always protected him.