首楞嚴義疏注經 3.425

3.425

「出土一尺，於中則有一尺虛空，如是乃至出土一丈，中間還得一丈虛空，虛空淺深隨出多少。此空為當因土所出？因鑿所有？無因自生？」

"if they remove one foot of soil, then within it there is one foot of space; and so on, even up to removing one zhang of soil, they obtain one zhang of space within it. The depth of the space follows the quantity removed. Does this space come out because of the soil? Does it exist because of the digging? Or does it arise causelessly on its own?"