(20) باب جَوَازِ اسْتِتْبَاعِهِ غَيْرَهُ إِلَى دَارِ مَنْ يَثِقُ بِرِضَاهُ بِذَلِكَ وَيَتَحَقَّقُهُ تَحَقُّقًا تَامًّا وَاسْتِحْبَابِ الاِجْتِمَاعِ عَلَى الطَّعَامِ
Anas b. Malik reported this hadith (with a slight variation of wording) Then AlIah's Messenger (ﷺ) ate and the people of his house also ate. but (still) there was left a surplus, which they sent to their neighbours.
Reference: Sahih Muslim 2040 f
In-book reference: Book 36, Hadith 195
USC-MSA web (English) reference(deprecated numbering scheme): Book 23, Hadith 5063