Al-Kāfi - Volume 6 > Wudu (washing hands clean) before and after Food
Hadith #4

عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ النَّوْفَلِيِّ عَنِ السَّكُونِيِّ عَنْ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) قَالَ مَنْ سَرَّهُ أَنْ يَكْثُرَ خَيْرُ بَيْتِهِ فَلْيَتَوَضَّأْ عِنْدَ حُضُورِ طَعَامِهِ .

4. Ali ibn Ibrahim has narrated from his father from al-Nawfaliy from al-Sakuniy who has said the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘If one likes to see blessings in his house to increase, he must take wudu for taking food.’”