I find it expressed in various passages of Scripture that the fact that God knows things while in a state of possibility, when their existence belongs to the future, does not change the nature of the possible in any way; that nature remains unchanged; and the knowledge of the realisation of one of several possibilities does not yet effect that realisation. This is likewise one of the fundamental principles of the Law of Moses concerning which there is no doubt nor any dispute.
"Guide for the Perplexed". Book Maimonides, Ch.20, 1190.