"The Messenger of Allah said: 'Pre-emption is to be given in everything that is shared, whether it is a house or a garden. It is not right to sell it before informing one's partner, and if he sells it he (the partner) has more right to it, unless he gives Permission to sell it to someone else.  

قَالَ رَسُولُ اللَّهِ ﷺ الشُّفْعَةُ فِي كُلِّ شِرْكٍ رَبْعَةٍ أَوْ حَائِطٍ لاَ يَصْلُحُ لَهُ أَنْ يَبِيعَ حَتَّى يُؤْذِنَ شَرِيكَهُ فَإِنْ بَاعَ فَهُوَ أَحَقُّ بِهِ حَتَّى يُؤْذِنَهُ