7930. To inflict the plague' means damnation which they bring on themselves. This is clear from the meaning of 'the plague' here as the damnation of those belonging to the spiritual Church who have been governed by faith separated from charity, dealt with in 7879, 7926. Regarding damnation, that the ones to inflict it on the evil are the evil themselves, see just above in 7926.
7930a 'And you shall keep this custom as a statute for yourself and your children for evermore' means that all this will be in keeping with Divine order as it will apply from now on to those belonging to the spiritual Church. This is clear from the meaning of 'keeping this custom for evermore' as that all this is to be observed from now on; from the meaning of 'as a statute' as in keeping with order, dealt with in 7884; and from the representation of the children of Israel, [to whom 'yourself and your children' refers here,]a as those who belong to the spiritual Church, dealt with in 4286, 6426, 6637, 6862, 6868, 7035, 7062, 7198, 7201, 7215, 7223. The order meant here is that which has existed in heaven since the time that the Lord, from His Divine Human, began to bring order to all things in heaven and on earth, which was immediately after the Resurrection, Matt 28:18. In keeping with this new order those belonging to the spiritual Church could now be raised to heaven and enjoy eternal blessedness; it could not be done in keeping with the old order. Formerly the Lord brought things into order by means of heaven; but latterly He did so by means of His Human which He glorified and made Divine in the world. The glorification of His Human brought so great an increase of might that those were raised to heaven who could not be raised previously, and also so great an increase that the evil departed from all around and were shut away in their hells. This order is what is meant here.