Al-Matalib al-'Aliyah 1755 — Breastfeeding

It is narrated from Sayyiduna al-Mughirah bin Shu'bah (may Allah be pleased with him) that he said: "(Nursing by way of) 'al-'ayfah' does not establish the prohibition of marriage." We asked: "What is meant by al-'ayfah?" He explained: "(Al-'ayfah is that) when a woman gives birth and the milk becomes blocked in her breasts and makes them heavy, and then her servant or some girl sucks it once or twice (to relieve that discomfort), (then no foster relationship is established by it)."
From this athar the scholarly point becomes clear that merely sucking milk does not establish the prohibition of fosterage unless it falls within the legally fixed quantity and the specific age of nursing.