The Ancient Law by Ellen Glasgow

In his nightly work in the Brookes' garden, Ordway was prompted at first by a mere boyish impulse to repay people whose bread he had eaten and in whose straw he had slept. But at the end of the first hour's labour the beauty of the moonlight wrought its spell upon him, and he felt that the fragrance of the lilacs went like strong wine to his head. So the next night he borrowed Mrs. Twine's spade again and went back for the pure pleasure of the exercise; and the end of the week found him still digging among the last year's plants in the loamy beds. By spading less than two hours a night, he had turned the soil of half the garden before Sunday put a stop to his work.

On his last visit, he paused at the full of the moon, and stood looking almost with sadness at the blossoming lilacs and the overgrown path powdered with wild flowers which had strayed in through the broken fence. For the hours he had spent there the place had given him back his freedom and his strength and even a reminiscent sentiment of his youth. While he worked Lydia had been only a little farther off in the beauty of the moonlight, and he had felt her presence with a spiritual sense which was keener than the sense of touch.