增壹阿含經 17.1.p3

17.1.p3

At this time, Venerable Rāhula thought, “For what reasons, today, on the path to the city walls, has the Bhagavān faced me and admonished me in this manner? I will return now, as I ought not enter the city walls of Śrāvastī to beg for food.” Then Venerable Rāhula promptly returned along the road to the Jeta Grove Monastery. Arriving there with his robe and bowl, he stopped below a tree. Correcting his body and correcting his intention, he sat cross-legged, focusing his energy single-mindedly. He was mindful of the impermanence of form, and mindful of the impermanence of sensation, conception, synthesis, and discrimination.