Sayyiduna al-Zubayr (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him) that he (peace and blessings be upon him) said: "Suckling once or twice does not establish the prohibition (of marriage) through breastfeeding."
Hadith Referenceالمعجم الكبير للطبراني / العشرة / 247