Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 19
Sanskrit:
वन्यैश्चरुपुरोडाशान् निर्वपेत् कालचोदितान् ।लब्धे नवे नवेऽन्नाद्ये पुराणं च परित्यजेत् ॥ १९ ॥
ITRANS:
vanyaiś caru-puroḍāśānnirvapet kāla-coditānlabdhe nave nave ’nnādyepurāṇaṁ ca parityajet
Translation:
A vānaprastha should prepare cakes to be offered in sacrifice from fruits and grains grown naturally in the forest. When he obtains some new grains, he should give up his old stock of grains.