ENOfficial
Umm Salama reported God’s Messenger as saying, “The only suckling which makes marriage unlawful is that which is taken from, the breast and enters the bowels, and is taken before the time of weaning.” Tirmidhi transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ أُمِّ سَلَمَةَ قَالَتْ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «لَا يُحَرِّمُ مِنَ الرِّضَاعِ إِلَّا مَا فَتَقَ الْأَمْعَاءَ فِي الثَّدْيِ وَكَانَ قبل الْفِطَام» . رَوَاهُ التِّرْمِذِيّ
sunnah.com