To change the past, you don't need to travel in a time machine. You can do it remotely.
This is how it works: From beyond the timeline, God observes your situation at this very moment. From there, He creates all things—the now, the future, and the past.
With each new moment of "now," the entire past is also regenerated as if it never happened. Change the present now, and you will have changed the past as well.
B"H I understand how I can change the future by how I behave today—but the past, already done, only if I repent, could He change my past—could you elaborate a little more on your explanation?—Shavua Tov
B"H
Hello, there are several points to consider.
1) Hashem is not limited by time. We, as human beings, live subject to time and space. Hashem creates time and space, so for Him, there is no time and space. He is not governed by time. That is why, for example, the question "How old is Hashem?" is meaningless because that question implies that Hashem is being governed by an absolute timescale, by which we measure all things, and in reality, He creates that timescale under which we and all creatures live, except for Him.
Therefore, when Hashem recreates all of creation at every instant, He not only creates the present, but also creates the past and future of that person as He wills. He could, for example, create us at a specific moment with a different past and a different future. Hashem is not limited by anything, except when He limits Himself (for example, when our sages say that Hashem chose the Jewish people "and cannot change them" for another people. The "cannot" is because He chose not to. And yet, at a certain level, that of His essence, He could...).
2. There is a level of Teshuvah, when it is done out of love for God, in which sins committed intentionally are transformed into merits. Ordinary Teshuvah ensures that these sins do not detract from merit, while Teshuvah done out of love transforms them into merit. Thus, we see that it is possible to change the past by changing one's present relationship with God.
From these points, the idea behind this thought is that when one reaches the essence of one's own soul, which is directly linked to the essence of Hashem, one accesses a level that transcends time and space. Therefore, one can modify the rules of time as we know it, as something linear and always progressing. From that place, one can regenerate time...
I hope that's clearer...