وَ كَتَبَ مُحَمَّدُ بْنُ اَلْحَسَنِ اَلصَّفَّارُ رَحِمَهُ اَللَّهُ إِلَى أَبِي مُحَمَّدٍ اَلْحَسَنِ بْنِ عَلِيٍّ عَلَيْهِ اَلسَّلاَمُ: فِي رَجُلٍ اِشْتَرَى مِنْ رَجُلٍ بَيْتاً فِي دَارٍ لَهُ بِجَمِيعِ حُقُوقِهِ وَ فَوْقَهُ بَيْتٌ آخَرُ هَلْ يَدْخُلُ اَلْبَيْتُ اَلْأَعْلَى فِي حُقُوقِ اَلْبَيْتِ اَلْأَسْفَلِ أَمْ لاَ فَوَقَّعَ عَلَيْهِ اَلسَّلاَمُ "لَيْسَ لَهُ إِلاَّ مَا اِشْتَرَاهُ بِاسْمِهِ وَ مَوْضِعِهِ إِنْ شَاءَ اَللَّهُ".
Muhammad bin Al-Hasan Al-Saffar, may Allah (swt) have mercy on him, wrote to Abu Muhammad Al-Hasan bin Ali (a.s) regarding a man who purchased a house in a property with all its rights, and there was another house above it. He asked whether the upper house is included in the rights of the lower house or not. Imam (a.s) responded: "He is entitled only to what he purchased by its name and specified location, if Allah (swt) wills."