One verse

Srimad Bhagavatam 11.18.5

11.18.5

अग्निपक्वं समश्न‍ीयात् कालपक्व‍मथापि वा । उलूखलाश्मकुट्टो वा दन्तोलूखल एव वा ॥ ५ ॥

agni-pakvaṁ samaśnīyāt kāla-pakvam athāpi vā ulūkhalāśma-kuṭṭo vā dantolūkhala eva vā

agni
by fire
pakvam
made ready to eat
samaśnīyāt
one should eat
kāla
by time
pakvam
right for eating
atha
else
api
indeed
vā
or
ulūkhala
with grinding mortar
aśma
and stone
kuṭṭaḥ
pulverized, ground up
vā
or
danta
using the teeth
ulūkhalaḥ
as a grinding mortar
eva
indeed
vā
or, alternatively

One may eat foodstuffs prepared with fire, such as grains, or fruits ripened by time. One may grind one’s food with mortar and stone or with one’s own teeth.