What is the ruling on reclaiming five meters of a street after having relinquished them for ten years, without causing harm to anyone?

If a person waives a portion of their land to widen a road, with the intention that it becomes part of the road, or declares such an intention, then the land ceases to be their property and becomes a public endowment (waqf) for the Muslims. They are not permitted to reclaim it. An endowment is a binding contract that cannot be revoked, and it remains perpetually dedicated for public benefit.