He—may Allah Most High have mercy on him—was asked:

“A man suffered from inflammation of the eyes and washed them with his wife’s milk. Does she become forbidden to him if her milk reaches his stomach?

“Another man loves his wife and, while playing intimately with her, suckled some of her milk. Does she become forbidden to him?”

He replied:

Praise be to Allah. Washing his eyes with his wife’s milk is permissible, and his wife does not thereby become forbidden to him, for two reasons.

First, he is an adult. If an adult suckles milk from his wife or another woman, this does not establish the marriage prohibitions arising from breastfeeding, according to the four Imams and the overwhelming majority of scholars, as indicated by the Quran and the Sunnah. They regard the hadith narrated by ‘Ā’ishah concerning Sālim, the freedman of Abū Hudhayfah, as specific to that case, because they had adopted him before adoption was prohibited.

Second, milk entering the eye does not establish these marriage prohibitions, and I know of no disagreement concerning this. Scholars have, however, differed over milk administered through the nose, following their disagreement over milk poured into the mouth without suckling. Most scholars hold that pouring milk into the mouth establishes the marriage prohibitions; this is the better-known of the two positions reported from Ahmad. Likewise, administering milk through the nose establishes these prohibitions according to one of the two positions reported from him. This is also the position of Abū Hanīfah and Mālik. Al-Shāfi‘ī has two opinions on the matter.

The answer to the second question is that his suckling does not make his wife forbidden to him according to the schools of the four Imams.