[Alas Babylon!]

It almost makes sense in light of this sentence:

The hilltop's hard, rocky soil would have been a tough place to dig graves.

A lot easier to dig a 2 foot square hole 6 feet deep than a six by 3 foot hole 6 feet deep in that kind of ground.

[AFreeBird]

The simplest answer is usually the best answer.

[eartrumpet]

A lot easier to dig a 2 foot square hole 6 feet deep than a six by 3 foot hole 6 feet deep in that kind of ground.

It's easier to pull rocks out when digging a ditch than it is when digging a posthole.