I might think, on any festival that they desire; it is, therefore, written (here) "and you shall come there … and you shall bring there." If to permit them, they have already been permitted. If to make them mandatory, they have already been made mandatory. If so, why is it written "and you shall come there … and you shall bring there'? To make them mandatory on the first fixed festival that presents itself.
I might think that if one festival passed and he did not bring it he is in transgression of (Ibid. 23:22) "You shall not delay to pay it"; it is, therefore, written "These shall you offer to the L-rd on your festivals" — he is not in transgression thereof until all the festivals of the year have passed.