The Entire Torah is in the Word Bereishis:
Sefer Aleph Kesav (page 51, Ois 132) writes that when the Vilna Gaon zy”a was in self-imposed exile, he once came to the city of Berlin. He had with him a notebook and various papers on which he wrote his chiddushei Torah. One day, he was in the home of a balhabos when a paper fell from his pocket onto the ground. The balhabos picked it up and looked at it. He saw that the Gaon had written, “The entire Shas, Tosefta, Mechilta, and Medrashim are all hinted to in the Written Torah. And the entire Written Torah is hinted to in Sefer Bereishis. And the entire Sefer Bereishis is hinted to in the word Bereishis.”
The balhabos asked, “I just had my firstborn son, and I am obligated to make a pidyon haben. How is that hinted to in the word Bereishis.”
The Gaon answered, “The word ‘Bereishis’ is an acronym for ‘bincha rishon achar shloshim yom tifdeh.’” (You firstborn son, after 30 days you shall redeem him.)