Nafi reported,

Ibn Umar performed the funeral prayer over nine deceased persons together. He placed the men closest to the imam and the women closest to the qiblah, arranging the women in a single row.The body of Umm Kulthum bint Ali, the wife of Umar bin Khattab, was placed alongside that of her son named Zayd, the two of them set down together. The imam that day was Saeed bin As, and among the people present were Ibn Umar, Abu Hurairah, Abu Saeed, and Abu Qatada. The boy was placed in the position closest to the imam.A man said, "I found this strange, so I looked toward Ibn Abbas, Abu Hurairah, Abu Saeed, and Abu Qatada and asked, 'What is this?'"They replied, "This is the sunnah."

Azami 3688

Sahih

عن نافع

أن ابن عمر صلى على تسع جنائز جميعا، فجعل الرجال يلون الإمام، والنساء يلين القبلة، فصفهن صفا واحدا، ووضعت جنازة أم كلثوم بنت علي امرأة عمر بن الخطاب وابن لها يقال له: زيد وضعا جميعا، والإمام يومئذ سعيد بن العاص، وفي الناس ابن عمر وأبو هريرة وأبو سعيد وأبو قتادة، فوضع الغلام مما يلي الإمام، فقال رجل: فأنكرت ذلك، فنظرت إلى ابن عباس وأبي هريرة وأبي سعيد وأبي قتادة، فقلت: ما هذا؟ قالوا: هي السنة.

الأعظمي 3688صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Funerals
Chapter
Prayer over the deceased
Section
Order of placing the bodies of men, women, and children when they are together
Numbering
Jami al-Kamil 3688 (2nd edition)
Azami 3688