If they say that it is by his own choice, we will say that he has not done anything. Only Allah knew that he will not allow the apostle and knowing this does not justify that he should be bound by duties, which he does not know. If this should be fair, then it is fair that anyone should be bound by duties he does not know when Allah knows that he will not consider them. It is an absurd supposition. Thus it must be said that Allah will send the apostle to him and require him to submit to him to eliminate any legitimate excuse, and then He will protect His apostle through means, which do not violate free-will, or renders him unable to kill the apostle, in which case he will not be able to reach him through his own acts. This is our same situation with the Imam during occultation.