Muwatta Malik #1148
Marriage
The Arabic includes the chain of narration (sanad) and the collector's commentary; the English translation shows the Prophet's words only.
حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ مُحَمَّدِ بْنِ يَحْيَى بْنِ حَبَّانَ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ
" لاَ يَخْطُبُ أَحَدُكُمْ عَلَى خِطْبَةِ أَخِيهِ " .
Yahya related to me from Malik from Muhammad ibn Yahya ibn Habban
from al-Araj from Abu Hurayra that the Messenger of Allah, may Allah
bless him and grant him peace, said, "Do not ask for a woman in
marriage when another muslim has already done so."
About Muwatta Malik
This hadith is #1148 from Muwatta Malik, in the Book of Marriage.