A student of mine quoted something in reference to a famous symbol on Ryoanji Temple which basically means, "I only know what is eough." He said the symbol was based on the last teaching of the Buddha before he died. He quoted that teaching as, “You Bhikku! If you want to escape from suffering, you have to comprehend the realization of enough. The basis of realizing enough is comfort and peace. The one who realizes enough would be comfortable even if he slept on the ground. The one who does not realize enough would be uncomfortable even if he were in palace. The one who does not realize enough would be poor even if he were rich. The one who realizes enough would be rich even if he were poor. That is called realizing enough.”
Any ideas on which sutra this quotation may have come from? I had guessed the Mahaparinirvana Sutra, but I'm not sure this is so.