You can find this exercise on page 93 of the book Synergistic Golf.
Exercise Type: DB STRENGTH
Exercise Category: CHEST, POWER PRODUCTION, SHOULDERS, STRENGTH
Similar to regular punches, shifting and punching from side to side, but aim arms across body toward corners of ceiling over head. Maintain form and increase weight when needed. Use 3-5-8lb dumbbells. Repeat 20x each side.