Unenlightened monks indebtedness to the laity
This is covered in the Cūlaccharāsanghāta Sutta, this was preached to counter the  Aggikkhandhopama Sutta, which was said to frighten many monks back to lay life , or to "disrobe". This is supposedly (link) said in the Manorathapūranī, the commentary by Buddhaghosa on the Aṅguttara-nikāya.