The Long Āgama Sūtra 26.30

26.30

佛言：「譬如有人立梯空地，餘人問言：『立梯用為。』答曰：『我欲上堂。』又問：『堂何所在？東、西、南、北耶？』答云：『不知。』云何？婆悉咤！此人立梯欲上堂者，豈非虛妄耶？」

The Buddha said, “They are like a man who builds a ladder in an empty place. Someone else asks him, ‘What’s the purpose of building a ladder here?’

“The man answers, ‘I want to ascend the hall.’

“Again, he’s asked, ‘Where is this hall? Is it east, west, south or north of here?’

“He answers, ‘I don’t know.’

“How is it, Vāsiṣṭha? Didn’t this man who built a ladder to ascend a hall do so in vain?”