Why can only one sign be shaken out when calculating divination?

The number of great divination is fifty, and nine out of forty is used to avoid one, and this "first" is an opportunity of life and also an opportunity for God to regret, which is why there can only be one divination, and if there are two divinations, one is good and the other is bad, which one do you choose? Since you choose divination, you can't make a choice, so you can ask God through divination.