15. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad ibn ‘Isa from Mu’ammar ibn Khallad who has said the following: “I once heard al-Rida’ عليه السلام, saying, ‘If one eats food in his house and pieces fall, he must pick them up; but if one eats in wilderness or out of the house he can leave such pieces for the birds and beasts.’”