Sayyiduna Uqbah bin Amir (may Allah be pleased with him) also narrated a similar hadith from the Noble Prophet (peace and blessings be upon him), except that in it, he said: The Prophet (peace and blessings be upon him) said: If you exercise ijtihad and reach the correct decision, you will receive ten rewards, and if you exercise ijtihad and make a mistake, you will receive one reward.
Hadith Referenceالفتح الربانی / مسائل القضاء والشهادات / 6387