This is one of Nantembo's signature themes, Daruma "Wall-gazing," i.e., contemplating the Absolute as he sits in his cave. However, Nantembo goes on to joke, "If form is all there is to Zen meditation, then the melons and the eggplants from Yahata [by Nantembo's temple] are sitting just as well as Daruma and taste good besides." In other words, take the core, not just the peel, of Zen.
Nantembo was one of the more colorful Zen masters of recent times. He was famed for disciplining his disciples with a stout staff made from a branch of a nanten tree, hence his nickname Nantembo, "Nanten-stick." He was a friend of the great swordsman Yamaoka Tesshu, and had many important and influential disciples. Nantembo was said to have had more than three thousand Zen students and he is believed to have created around one hundred thousand works of Zen art.