Jñāneśvarī (commentary on the Bhagavadgītā) 2.184

2.184

agā gokṣīra jarī jāhaleṃ |
tarī pathyāsi nāhīṃ mhaṇitaleṃ |
aisenihi viṣa hoya sudaleṃ |
navajvarīṃ detāṃ ||

O friend, even though it be cow’s milk, / it is not prescribed as wholesome diet [in sickness]; / in just such a way, it acts as poison / if given during a fresh fever.