Husband rolled ankle, its swollen and bruised, painful too touch.?

If he can stand. it is 99% likely it is only an ankle sprain. The common ankle sprain has immediate swelling pain, sometimes a pop and tenderness on the front and outside of the ankle. Typically the foot rolls in. An ankle sprain is in essence a misnomer. The ligaments in the ankle don't actually "sprain" they tear and bleed causing the bruising. Treat with ICE, nsaids, ace wrap, range of motion, Bracing.
He needs evaluation. Bruising usually indicates ligament damage. In very least get an X-ray to make sure no fracture. See a specialist to see if there is soft tissue injury.