the Messenger of Allah ﷺ ruled concerning preemption of land that has not been divided; if the boundaries have been set then there is no preemption.
أَنَّ رَسُولَ اللَّهِ ﷺ قَضَى بِالشُّفْعَةِ فِيمَا لَمْ يُقْسَمْ فَإِذَا وَقَعَتِ الْحُدُودُ فَلاَ شُفْعَةَ