Al-Kāfi
Hadith 1298عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ أَحْمَدَ بْنِ أَبِي عَبْدِ اللَّهِ عَنْ مُحَمَّدِ بْنِ عِيسَى عَنْ أَبِيهِ عَنْ جَدِّهِ وَ قَيْسِ بْنِ عَبْدِ الْعَزِيزِ عَنْ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) قَالَ مُخُّ الْبَيْضِ خَفِيفٌ وَ الْبَيَاضُ ثَقِيلٌ .
5. A number of our people have narrated from Ahmad ibn abu ‘Abd Allah from Muhammad ibn ‘Isa from his father from his grandfather and Qays ibn ‘Abd al-’Aziz who has said the following: “Abu ‘Abd Allah (a.s.), has said, ‘The egg yoke is light and its white is heavy.’”