Recently adopted a dog and it keeps whining early in the morning.

While many website encourage to ignore the whining, it is not feasible as neighbors are sensitive to noise.

So far I won't put the leash until he sit. Trying not to reinforce the whining behaviour. But today it whine since 5.45am until I come out and the neighbor is not happy with it. Usually I let him out at 6am.

How do you stop dog whining?