Mattityahu 18:21-22

Then, having approached, Kefa said to Rebbe, Melech HaMoshiach: Adoni, how often will my brother sin against me and I will grant to him selicha (forgiveness)? As many as shevah (seven) times? Rebbe, Melech HaMoshiach says to Kefa, I do not say to you as many as shevah, but as many as shivim (seventy) times shevah.