(Mufti. Shah Rafi Uddin Hamdani & Dr. Imran Khan)
Foster brothers and sisters are those relatives who are related because they suckled from the same woman. ProphetMuhammad was suckled by various women, therefore he had numerous foster brothers and sisters. Their details are given below:
 was suckled by various women, therefore he had numerous foster brothers and sisters. Their details are given below:
 Through Thuwaybah 
 . He was a paternal uncle of the Holy Prophet
. He was a paternal uncle of the Holy Prophet but since they had suckled from the same woman, he was his foster brother as well.
 but since they had suckled from the same woman, he was his foster brother as well. who was the son of Prophet Muhammad’s
 who was the son of Prophet Muhammad’s  paternal aunt. Hence, he was his cousin and foster brother.
 paternal aunt. Hence, he was his cousin and foster brother. was Thuwaybah’s
 was Thuwaybah’s  own son who became a foster brother to Prophet Muhammad
 own son who became a foster brother to Prophet Muhammad  . 1
. 1 . He was his cousin and his foster brother.
. He was his cousin and his foster brother. was a paternal cousin and a foster brother of the Holy Prophet
 was a paternal cousin and a foster brother of the Holy Prophet  . 2
. 2 Through Halimah Sadiya 
 was Halimah Sadiya’s
 was Halimah Sadiya’s  own son who became  Prophet Muhammad's
 own son who became  Prophet Muhammad's  foster brother.
 foster brother. were daughters of Halimah Sadiya
 were daughters of Halimah Sadiya  who became Prophet Muhammad's
 who became Prophet Muhammad's  foster sisters.
 foster sisters. ibn Harith ibn Abdul Muttalib who was a distant paternal cousin of the Holy Prophet
 ibn Harith ibn Abdul Muttalib who was a distant paternal cousin of the Holy Prophet  , became his foster brother as well. 3
, became his foster brother as well. 3Islam gave these nursing mothers and relations a special status in the family. If a child is reared and breastfed by a woman other than the real mother, she is called Umm-e-Rada'ah (ام رضاعۃ) (foster mother, or milk mother). Her children are treated as real brothers and sisters and marrying with them is prohibited. Thus, a woman who nurses a child, becomes mother by milk-relation. Her suckled child is considered as a full sibling to the foster-mother’s other children, and as mahram to the woman. Islam stands unique to accord such a status to the suckling mothers.