Sayyidah Aishah (may Allah be pleased with her) said: When the Prophet (peace and blessings be upon him) intended to travel, he would cast lots among his wives, and whichever wife's lot came out, he would take her with him.
Imam al-Shafi'i (may Allah have mercy on him) said: This applies to everyone among people who has wives. Imam al-Shafi'i (may Allah have mercy on him) also said: And among that is that he intended to part from Sawdah, and she said: "Do not part from me; leave me so that Allah, the Mighty and Majestic, resurrects me among your wives, and I give my day and my night to my sister Aishah (may Allah be pleased with her)."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13432