これほどの投資が短期間に寄せられことは珍しく銀行にとって千載一遇のチャンスだと話していました。

He said it was a rare opportunity for the bank to receive such a large amount of investment in such a short period of time.

引用元(reference)：https://www3.nhk.or.jp/lnews/kumamoto/20221104/5000017399.html

意味：滅多に訪れそうもないよい機会。二度と来ないかもしれないほど恵まれた状態。
Meaning:A good opportunity that is unlikely to come along. A state so blessed that it may never come again.