Is it true that whoever says, "I seek forgiveness from Allah, the Most High, the Most Great, Whom there is no god but He, the Ever-Living, the Self-Subsisting, and unto Him I repent" three times will have all their sins forgiven?

It is authentically reported from the Prophet, peace and blessings be upon him, that whoever says: "I seek forgiveness from Allah, the Magnificent, whom there is no god but He, the Ever-Living, the Sustainer, and I repent to Him," his sins will be forgiven, even if he fled from battle. However, restricting it to three times is not authentically reported.