((مَنْ أَطْعَمَهُ اللَّهُ الطَّعَامَ فَلْيَقُلْ: اللَّهُمَّ بَارِكْ لَنَا فِيهِ وَأَطْعِمْنَا خَيْراً مِنْهُ، وَمَنْ سَقَاهُ اللَّهُ لَبَناً فَلْيَقُلْ اللَّهُمَّ بَارِكْ لَنَا فِيهِ وَزِدْنَا مِنْهُ)).
(Whomever Allah feeds, should say:(O Allah, bless it for us and feed us better than it.) and whomever Allah gives milk to drink should say:(O Allah, bless it for usand give us more of it.))
At-Tirmidhi 5/506. See also Al-Albani, Sahih At-Tirmidhi 3/158.