Suppose a third person is legally entitled, under the relevant rules, to shuf'ah (pre-emption) in a property transaction. The original buyer and seller then agree to iqalah.
For the parties, that agreement unwinds their sale; for the qualifying third-party pre-emptor, it can count as a new sale for purposes of the pre-emption right.
This does not automatically grant pre-emption to every neighbour: standing and procedural conditions belong to a distinct legal chapter.