Final answer:
Arnold Palmer referred to the Masters golf tournament course, which is known for being played on well-maintained grass, not on clay, sand, or ice.
Step-by-step explanation:
The Masters is a prestigious golf tournament that is known for its immaculate condition and challenging play. Arnold Palmer, a legendary golfer, once referred to the Masters course, implying that it is played on beautifully maintained grass. This comment highlights the smooth, uniform nature of the course, where the fairway, rough, and hazards are not as distinctly separated as they might be on other golf courses, hence giving it a 'velvet' texture that resembles a seamless green.