This roll of caligraphy shows kanji-written mantra by Musashi Miyamoto. This work is a genuine one. According to the ledend, Musashi wrote the first two kanji words by his right hand, and wrote the rest with his left hand. I think that he always used both hands intentionally in his daily life and as his own daily practice of using his hands for improving his fencing skill/
Musashi used to stay at a temple called Toko-in Temple in Nagoya. When Musashi stayed there, he reportedly introduced his own fencing style to local people and practiced with them his own fencing style in order to promote his own fencing style in the district. The temple is just in front of Kasa-dera Temple in current Minami Ward, Nagoya City.