首楞嚴義疏注經 1.114

1.114

城之濠塹曰隍。齋莊齊整，不失威儀，安靜恭謹，足成令則。以斯行乞，物無不從，仰効尊儀，故云齋法也。

"The ditch and trench of a city wall is called a moat. Dignified and orderly, not losing majestic deportment, tranquil and reverent, this was fully sufficient to serve as an admirable model. Begging alms in this manner, no creature would fail to follow. Looking up to and emulating the Venerable One's deportment, it is therefore called 'the rules of vegetarian alms'.