Sunan Abi Dawud 1517
سنن أبي داود#1517SahihNarrated Zayd, the client of the Prophet: The Prophet (ﷺ) said: If anyone says: "I ask pardon of Allah than Whom there is no deity, the Living, the eternal, and I turn to Him in repentance," he will be pardoned, even if he has fled in time of battle
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih Lighairihi
Zubair Ali ZaiHasan
In-book reference: 8:102