Whenever Messenger of Allah ﷺ wanted to go on a journey, he would draw lots as to which of his wives would accompany him. He would take her whose name came out. He used to fix for each of them a day and a night. But Sauda bint Zamʿa gave up her (turn) day and night to ʿAisha, the wife of the Prophet in order to seek the pleasure of Messenger of Allah ﷺ (by that action).
كَانَ رَسُولُ اللَّهِ ﷺ إِذَا أَرَادَ سَفَرًا أَقْرَعَ بَيْنَ نِسَائِهِ فَأَيَّتُهُنَّ خَرَجَ سَهْمُهَا خَرَجَ بِهَا مَعَهُ وَكَانَ يَقْسِمُ لِكُلِّ امْرَأَةٍ مِنْهُنَّ يَوْمَهَا وَلَيْلَتَهَا غَيْرَ أَنَّ سَوْدَةَ بِنْتَ زَمْعَةَ وَهَبَتْ يَوْمَهَا وَلَيْلَتَهَا لِعَائِشَةَ زَوْجِ النَّبِيِّ ﷺ تَبْتَغِي بِذَلِكَ رِضَا رَسُولِ اللَّهِ ﷺ