بلوغ المرام
كتاب النكاح
Book 8, Hadith 1042
الإسناد
المتن
وَلَهُ مِنْ حَدِيثِ جَابِرٍ نَحْوُهُ .‏ وَقَالَ : { فَإِنْ شَاءَ طَعِمَ وَإِنْ شَاءَ تَرَكَ } 1 ‏ .‏
Muslim has something similar to the above from the Hadith of Jabir (RA), it goes: "If he wishes he may eat, and if he wishes he may leave (the food alone)."