Musnad Ahmad 30:3718

'Abd al-Samad narrated to us, Shu'bah narrated to us, from al-A'mash, from Abu Salih, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "A man shall not make an offer on the offer of his brother, and he shall not propose to the proposal of his brother."