She said that when God’s Messenger intended to go on a journey he cast lots among his wives and the one who was chosen by lot went on it with him. (Bukhari and Muslim.)

وَعَنْهَا قَالَتْ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا أَرَادَ سَفَرًا أَقْرَعَ بَيْنَ نِسَائِهِ فأيهن خَرَجَ سَهْمُهَا خَرَجَ بِهَا مَعَهُ