Sahih Al Bukhari Hadith Number 1332

Narrated Samura bin Jundab: I offered the funeral prayer behind the Prophet (peace be upon him) for a woman who had died during childbirth and he stood up by the middle of the coffin

23  Funerals (Al-Janaa’iz)
Hadith number 1332
Volume no 2
Chapter: 63 (Where should the Imam stand while leading the funeral prayer of a female or a male?)