Sahih Muslim | Book 8 | Hadith Number 3415

Narrated by Umm al-Fadl
Umm al-Fadl reported: A bedouin came to Allah's Apostle (may peace be upon him) when he was in my house and said: Allah's Apostle, I have had a wife and I married another besides her, and my first wife claimed that she had suckled once or twice my newly married wife, thereupon Allah's Apostle (may peace be upon him) said: One suckling or two do not make the (marriage) unlawful.