難行道  / nán xíng dào /
Difficult Path 
Category:
Buddhist Terminology 
Description:
歷經三大阿僧祇劫行菩薩道者,是為「難行道」。
To have practiced the Bodhisattva path for three asamkya-kalpas is what is called the "difficult path."
References:
星雲大師全集【書法類】中華文化佛教名詞 名相 The Complete Works of Venerable Master Hsing Yun: Calligraphy-Terminology 
高雄市大樹區興田里興田路 153 號
886-7-6561921 #2501-2506