The Prophet ﷺ said, "A single suckling or two sucklings do not establish the prohibition of marriage."
أخبرنا شعيب بن يوسف عن يحيى عن هشام قال حدثني أبي
عن النبي ﷺ قال لا تحرم المصة والمصتان
No references are available.
[Its isnad is sahih] Ahmad reported it: 4/4, from Yahya Qattan, through him, and it is in al-Kubra, no. 5456, and Ibn Hibban graded it sahih, no. 1251.