Deuteronomy 27:15

Cursed The curses are expressed, but not the blessings. For as many as were under the law, were under the curse. But it was an honour reserved for Christ to bless us; to do that which the law could not do. So in his sermon on the mount, the true mount Gerizim, we have blessings only. The man that maketh any graven image Under this particular he understands all the gross violations of the first table, as under the following branches he comprehends all other sins against the second table. Amen It is easy to understand the meaning of amen to the blessings. But how could they say it to the curses? It was both a profession of their faith in the truth of these curses, and an acknowledgment of the equity of them. So that when they said amen, they did, in effect, say, not only, it is certain it shall be so, but, it is just it should be so.