Sahih Muslim 2281
Sahih Muslim · Book 43: The Book of Virtues · The Miracles Of The Prophet (SAW)
Jabir reported that a person came to Allah's Apostle (ﷺ) and asked for food. And he gave him half a wasq of barley, and the person and his wife and their guests kept on making use of it (as a food) until he weighed it (in order to find out the actual quantity, and it was no more). He came to Allah's Apostle (ﷺ) (and informed him about it). He said:
وَحَدَّثَنِي سَلَمَةُ بْنُ شَبِيبٍ ، حَدَّثَنَا الْحَسَنُ بْنُ أَعْيَنَ ، حَدَّثَنَا مَعْقِلٌ ، عَنْ أَبِي الزُّبَيْرِ ، عَنْ جَابِرٍ ، أَنَّ رَجُلاً، أَتَى النَّبِيَّ صلى الله عليه وسلم يَسْتَطْعِمُهُ فَأَطْعَمَهُ شَطْرَ وَسْقِ شَعِيرٍ فَمَا زَالَ الرَّجُلُ يَأْكُلُ مِنْهُ وَامْرَأَتُهُ وَضَيْفُهُمَا حَتَّى كَالَهُ فَأَتَى النَّبِيَّ صلى الله عليه وسلم فَقَالَ " لَوْ لَمْ تَكِلْهُ لأَكَلْتُمْ مِنْهُ وَلَقَامَ لَكُمْ " .
Had you not weighed it, you would be eating out of it and it would have remained intact for you.