Dutiyaanagatabhayasutta 1.6

1.6

Jiṇṇena kho pana jarāya abhibhūtena na sukaraṃ buddhānaṃ sāsanaṃ manasi kātuṃ, na sukarāni araññavanapatthāni pantāni senāsanāni paṭisevituṃ.

When you’re old, overcome by old age, it’s not easy to focus on the instructions of the Buddhas, and it’s not easy to frequent remote lodgings in the wilderness and the forest.