Sahih Muslim 1463
Sahih Muslim · Book 17: The Book of Suckling · It is permissible for a wife to give her turn to a co-wife
A hadith like this has been transmitted on the authority of Hisham with the same chain of narrators (and the words are):
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ ، حَدَّثَنَا عُقْبَةُ بْنُ خَالِدٍ ، ح وَحَدَّثَنَا عَمْرٌو النَّاقِدُ ، حَدَّثَنَا الأَسْوَدُ بْنُ عَامِرٍ ، حَدَّثَنَا زُهَيْرٌ ، ح وَحَدَّثَنَا مُجَاهِدُ بْنُ مُوسَى ، حَدَّثَنَا يُونُسُ بْنُ مُحَمَّدٍ ، حَدَّثَنَا شَرِيكٌ ، كُلُّهُمْ عَنْ هِشَامٍ ، بِهَذَا الإِسْنَادِ أَنَّ سَوْدَةَ، لَمَّا كَبِرَتْ . بِمَعْنَى حَدِيثِ جَرِيرٍ وَزَادَ فِي حَدِيثِ شَرِيكٍ قَالَتْ وَكَانَتْ أَوَّلَ امْرَأَةٍ تَزَوَّجَهَا بَعْدِي .
When Sauda became old (the rest of the hadith is the same) and in the narration of Sharik there is an addition (of these words:" She was the first woman whom he (Allah's Apostle) married after me."