It is narrated from Abdullah bin Zubair (may Allah be pleased with them) that the Prophet (ﷺ) said: "Prohibition is not established by suckling once or twice."
Hadith Referenceمسند الإمام الشافعي / كتاب النكاح / 1183
Hadith Takhrijاخرجه مسلم، الرضاع، باب في المصة والمصتان (1450)۔