The Brazil international was rumored to be in talks with Al Nassr, with reports suggesting a potential salary of £1m per year.
Ederson told TNT: "I really had a good offer on the table, an offer that weighed heavily because it was an unusual offer.
"I also had countless conversations with (City manager Pep) Guardiola, and one of them was decisive.
"What he said - about guarantees, the process and the development I had under him - was decisive when I made the decision to stay at City."