I have heard this story from my teacher. He is a great person.
Japanese 『お遍路さん』(an Ohenro-San: 遍路=henro) is similar to a pilgrim in English. There are hallowed grounds of eighty eight places (temples) in Shikoku Island of Japan.
In this season Ohenro-Sans wear priest's robes and hats that are written by 『同行二人』(=walk together with the other person), and walk along roads in the country of Shikoku Island.
Why do they walk together with the other person although they are each only one person? Who is the other person? The other person is 『空海』(774-835)(Kuukai:空kuu=sky, 海kai=sea) who was a great monk of Buddhism and opened hallowed grounds of eighty eight places (temples) in Shikoku Island.
Ohenro-Sans always walk together with 『空海』, that is, 『空海』(=the truth or sanctity) keeps an eye on Ohenro-Sans. Life is same. We always live with 『空海』. 『空海』(=the truth or sanctity) means kindness, appreciation and a smile.
We are able to be useful even if we are old. This is 『同行二人』(=the truth or sanctity).