وَمَنْ بَاعَ دَارًا دَخَلَ فِي الْبَيْعِ مَفَاتِيحُ أَغْلَاقِهَا
Translation: Whoever sells a house, the keys of its locks are included in the sale.
Aghlaq are locks or closures, while mafatih are their keys.
Where locks are fixed accessories serving the house, the keys needed to operate them are treated as included. Handing over the premises while withholding the associated working keys would obstruct normal use and delivery.