What does the double divination mean in Yi Shu of Plum Blossoms?

Plum blossom easy number is a method of divination by numbers. Is to convert any information you receive into numbers, and then use the numbers for divination.

Double divination is a combination of upper divination and lower divination. Dynamic divination may be divination in the sky or in the sky. The upper divination or the lower divination represents the development of things, and the other divination represents yourself, because dynamic divination means moving, you won't move, but what happens around you will move. Next, let's talk about how to get numbers. Only with numbers can divination be done.