Hadith 200
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا عَبْدَةُ، قَالَ حَدَّثَنَا سَعِيدٌ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَاءُ الرَّجُلِ غَلِيظٌ أَبْيَضُ وَمَاءُ الْمَرْأَةِ رَقِيقٌ أَصْفَرُ فَأَيُّهُمَا سَبَقَ كَانَ الشَّبَهُ " .
It was narrated that Anas said:
"The Messenger of Allah (ﷺ) said: 'The man's water is thick and white, and the woman's water is thin and yellow. Whichever of them comes first, the child will resemble (that parent).'"
Reference : Sunan an-Nasa'i 200
In-book reference : Book 1, Hadith 201