The breastfeeding that renders marriage unlawful is five or more times during the first two years. If the woman breastfeeds the child in this manner, it becomes her milk-son and the milk-brother of all her children, even if her own child is more than two years old. What counts here is the age of the breastfed child and not the age of the woman's own child. Allah (Exalted be He) states:
Forbidden to you (for marriage) are: your mothers, your daughters
up to: (Part No. 21; Page No. 16)
...your foster milk suckling sisters
Allah also states:
The mothers shall give suck to their children for two whole years
Further, it is confirmed that the Prophet (peace be upon him) said:
"Milk-relations forbid what blood relations do."
It is related on the authority of
`Aishah (may Allah be pleased with her) that she said: "It was among the revelation of the Qur'an that ten known times of breastfeeding make the marriage prohibited, but this was later abrogated and reduced to five. The Messenger of Allah (peace be upon him) died and the ruling remained effective."One time of breastfeeding is when the child holds the breast and sucks milk. If the child leaves the breast and then holds it again to suck milk, this is considered a second time.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.