But he certainly hasn't let any grass grow under his feet.

"Don't let the grass grow under your feet" tells someone to get moving.

And he certainly hadn't let the grass grow under his feet!

But now, the ground had grown too slippery under his feet.

She was not one, however, to let the grass grow under her feet.

"Show him that the grass doesn't grow under my feet!"

Even the ground seems to grow and move under your feet.

"He never was one to let the grass grow under his feet," I said.

As you can see, we have not let the grass grow under our feet.

He went faster when the ground grew hot under his feet.