Why does Mr. Henderland rush into his house? What vow had he made? From chapters 13-16

Mr. Henderland had vowed never to carry snuff with him. He rushed in the room found a jar and took some snuff.

He burst rudely past me, dashed into the room, caught up a jar and a small horn-spoon, and began ladling snuff into his nose in most excessive quantities. Then he had a hearty fit of sneezing, and looked round upon me with a rather silly smile. "It's a vow I took," says he. "I took a vow upon me that I wouldnae carry it.