四分律比丘戒本 1.p28

1.p28

If a monk seek to get a house for himself, without a householder, on his own account alone, he must take care to observe the proper measurements; the mean measure ments are these, twelve of Buddha’s spans in length, and within, seven of these spans broad. He ought also to take the body of the monks, to mark out the position of the place given, in doing which they must observe the character of the place, that it be not either dangerous of approach or difficult of access; if the monk, notwithstanding the illegal position, still build his house, or if he take not the monks to inspect it, or if it exceed the lawful measurement, let him be suspended.