There is no transaction between two persons entering a transaction until they separate, but only when there is an option to annul it. (Using translation from Muslim 1531e)
قَالَ رَسُولُ اللهِ ﷺ «كُلُّ بَيِّعَيْنِ فَلَا بَيْعَ بَيْنَهُمَا حَتَّى يَتَفَرَّقَا إِلَّا بَيْعَ الْخِيَارِ»