A woman from the tribe of Banu Ghifar, whose name was given to me, reported, "The Messenger of Allah ﷺ seated me behind him on the back of his saddle. By Allah, the Messenger of Allah ﷺ kept traveling until morning. He then made his camel kneel, and I dismounted from the back of his saddle, only to find blood on it from me. It was my first menstrual period."She continued, "I drew myself close to the camel out of embarrassment. When the Messenger of Allah ﷺ saw my state and saw the blood, he asked, 'What is the matter with you? Perhaps you have begun your menses?'""Yes," I replied.He said, "Tend to yourself, then take a vessel of water, add salt to it, and wash off the blood that got on the saddle. Then return to your mount."She said, "When the Messenger of Allah ﷺ conquered Khaybar, he allotted us a portion of the spoils." She would never purify herself from menstruation without putting salt in her purifying water, and she left instructions that salt be placed in the water used to wash her body when she died.
حدثنا محمد بن عمرو الرازي حدثنا سلمة يعني ابن الفضل أخبرنا محمد يعني ابن إسحق عن سليمان بن سحيم
عن امرأة من بني غفار قد سماها لي قالت أردفني رسول الله ﷺ على حقيبة رحله قالت فوالله لم يزل رسول الله ﷺ إلى الصبح فأناخ ونزلت عن حقيبة رحله فإذا بها دم مني فكانت أول حيضة حضتها قالت فتقبضت إلى الناقة واستحييت فلما رأى رسول الله ﷺ ما بي ورأى الدم قال ما لك لعلك نفست قلت نعم قال فأصلحي من نفسك ثم خذي إناء من ماء فاطرحي فيه ملحا ثم اغسلي ما أصاب الحقيبة من الدم ثم عودي لمركبك قالت فلما فتح رسول الله ﷺ خيبر رضخ لنا من الفيء قالت وكانت لا تطهر من حيضة إلا جعلت في طهورها ملحا وأوصت به أن يجعل في غسلها حين ماتت
[Its isnad is daif] Ahmad narrated it: 6/380, from the hadith of Muhammad bin Ishaq bin Yasar, through this route.Umaya bint Abu Salt, her condition is unknown (Taqrib), and Ibn Ishaq is a mudallis, and he narrated with "an" (indicating possible discontinuity).