In Parshat Lech L'cha, we find a pasuk that mentions that Avraham was 86 years old when Hagar gave birth to Yishmael.
The very next pasuk (the beginning of the next parsha, a S'tuma) tells us that Avraham was 99 years old. Thirteen years elapsed in the blank space about as wide as 9 letters. We no nothing of what happened during those 13 years. And we don't know that because the Torah is not a diary or a journal.
It is the Book that G-d dictated to Moshe Rabeinu to give and teach to Bnei Yisrael and it is our guide to life throughout all the generations since Matan Torah until and beyond this very day. This guide, this Torah, contains mitzvot for us to observe and lessons of behavior we are to emulate, and other lessons of behavior that we must NOT adopt as our own. Whatever the Torah does tell us is meant to teach us and guide us.
The 13 year gap teaches us that. The Torah doesn't tell us things unless we are supposed to learn something. So when, at the beginning of Parshat Va'eira, the Torah tells us what G-d commanded to Moshe to say to Bnei Yisrael, that prophecy (and all the prophecies we find in Chumash and Tanach) is speaking to us - not just to our ancestors of 3329 years ago.
The first part - about G-d's taking us out of Egypt - V'HOTZEITI, V'HITZALTI, and V'GA'ALTI has been done and we need to know about it because of how crucial the Exodus is to us. So important that the first words that G-d spoke to the People directly clearly announce the fact that He is the One who took us out. Many mitzvot carry that reminder as well.
But technically, Y'tzi'at Mitzrayim has already happened. The second and third parts of that prophecy from was back then, are more ongoing. They repeat throughout Jewish History and apply to each Jew today in different ways.
G-d said He will take us to Him as a Nation. Done. He also said that He would be our G-d. That is not a done deal. Each Jew needs to make his own commitment to Torah and Mitzvot, so that G-d will be his. G-d said He will bring us to the Land of Israel. And that He will give it to us. He did and He continued to do that. And in some ways, each of us is challenged to do our part in the fulfillment of the prophecy. We are taught that the majority of the Jews in Egypt did NOT leave.
Even if we understand that all the Jews who made it to Sinai committed themselves to G-d with the unified pronouncement of NAASEH V'NISHMA, we know that many Jews today are not faithful to that commitment. We know too that coming to Eretz Yisrael and accepting that gift from HKB"H does not yet apply to us all. Where do you stand on your commitment and compliance to Torah and to Eretz Yisrael?