If this is a loan that is going to be repaid then I debt it would be seen as a gift for tax purposes. I would imagine the best way to prove this is being repaid and is a loan, not a gift, is to start immediately with recorded payments (e.g. direct debit from your account to the person who gave it to you).
Also you need to bear in mind that there are thresholds on accepting tax free gifts from direct family members and if you haven't received a gift from this person before then it is below the threshold and is tax free.
I think the limit to be considered a "large" transaction is 13k but I could be wrong. Over 13k may merit more checks by a financial institution on the source of the fund but if the 9k you're getting is kosher, then there isn't anything to worry about!!! I don't know if the CU has there own internal rules on this.