Avoiding taxes on a money gift in Germany

Question

I'll come to Germany for the first time in 2023 to study in a German university as a foreign student. I am from the country of Georgia. My mother will soon give me a money gift by transferring it from her Georgian bank account to my Georgian bank account before 2022 ends. At some point after I move to Germany in 2023, I will want to transfer that gifted sum from my Georgian bank account to a newly opened German bank account. My mother and I have never been subject to the German tax law. What documents will I have to present after I transfer the money gift from my Georgian bank account to my German bank account to prove that the gifting was indeed conducted before I became a German tax resident? Do we have to obtain an official notarised gifting agreement from a notary in our country? Or will a standard bank statement suffice?