the gemara on 4a says that a good nevuah can be reversed becaused of a sin. Yet on 7a the gemara says that a good nevuah even on condition is irreversable?
Shmuel Wagner, lakewood, nj
Excellent question. Your question is, in fact, discussed at length by Rav Eliyahu Mizrachi (the Re'em) to Bereishis 32:8, among others.
(a) The simple answer to your question seems to be that there is a difference between recalling a prophecy for a passive reason, and recalling a prophesy due to a positive action .
The Gemara on 7a tells us that an unfulfilled condition is not enough to revoke a promised reward, since there is no active reason to revoke it. However, the Gemara on 4a is telling us that a prophecy can indeed be revoked if a person actively sins, creating grounds for revoking the promised reward.
This is the answer offered by the RADVAZ 3:638 and the LECHEM MISHNAH in Yesodei Hatorah 10:4.
(b) However, the MAHARAL (in Gur Aryeh to Bereishis 32:8) takes a very different approach. He differentiates between a prophecy and a promise .
A prophecy will never be revoked, under any conditions. However, not every promise is a prophecy. The promise that Hash-m made to Yakov (that He will watch Yakov wherever Yakov goes etc.) did not have the status of a prophecy. Rather, Hash-m was telling Yakov that as a reward for Yakov's efforts to follow the will of Hash-m, Yakov earned the distinction that Hash-m would watch over him and protect him. Since this was promised based on Yakov's present level of G-d-fearingness, should Yakov sin, he would lose the promised protection.
I hope that you find this helpful. Best wishes,
Kollel Iyun Hadaf