From Rabash, Article “The Concept of the Yenika and Ibur”: This is called Ibur (impregnation) that he nullifies himself completely. But even though his heart tells him that only now does he agree with the nullification phase, afterwards he has regrets; about this we say, “Don’t be concerned about tomorrow!” And tomorrow is not exactly the day after today, rather today and tomorrow can be in the present.
What is important is what happens at each and every moment. And what will happen later is unknown to us. But our decision now will determine what will happen. Even though this is not certain because nobody knows the formula of how events will develop in the axis of time.
Therefore at each and every moment a person must only be concerned about the present moment because correction is not made in the past or the future, but only in the present. The main thing for correction is to adhere to the present moment.
And this is as the sages said: “Everyone who has something he can eat today but says, ‘what will I eat tomorrow?’ Well, this is a lack of faith” (Midrash Tanchuma, BeShlach 20).
From the 2nd part of the Daily Kabbalah Lesson 2/14/14, Writings of Rabash