Arcana Coelestia#6141
6141. 'And the ground may not become a waste' means that the mind must be cultivated with facts known to the Church. This is clear from the meaning of 'the ground' as the receptacle of truth, as above in 6135-6137, the actual receptacle being the mind, in this instance the natural mind since it is the ground of Egypt; and from the meaning of 'being laid waste' as a situation in which there is no truth to be seen, at this point no facts known to the Church, for 'the Egyptians' means the facts known to the Church, 4749, 4964, 4966, 6004, which are also the truths present in the natural. 'The land of Egypt' means the natural mind where factual knowledge resides, see 5276, 5278, 5280, 5288, 5701, and therefore 'the ground of Egypt' means that mind specifically. This now explains why 'the ground may not become a waste' means that the mind must be cultivated with facts [known to the Church].
Arcana Coelestia#5277
5277. 'And seven years of famine will arise after them' means subsequent states when there will be an absence of truth. This is clear from the meaning of 'years' as states, dealt with in 482, 487, 488, 493, 893; from the meaning of 'famine' as an absence of religious knowledge or cognitions. dealt with in 1460, 9364; and from the meaning of 'after them' as subsequent ones.