Imām Ibn al-Jawzī (d. 597/1201) summarized the scholars' opinions in his book "Zād al-Masīr" as follows:

1. The words: "Our Lord, we have wronged ourselves, and if You do not forgive us and have mercy upon us, we will surely be among the losers" (7: 23). [Ibn ʿAbbās, al-Ḥasan, Saʿīd ibn Jubayr, Mujāhid, ʿAṭāʾ al-Khurāsānī, ʿUbayd ibn ʿUmayr, Ubayy ibn Kaʿb, Ibn Zayd]
2. Adam said: "O Lord, did You not create me with Your own hands?" Allah said, "Yes." "Did You not breathe into me from Your spirit?" He said, "Yes." "Did Your mercy precede Your anger?" He said, "Yes." "Did You not command Your angels to prostrate to me, and did You not settle me in Your paradise?" He said, "Yes." He then asked, "O Lord, if I repent and reform, will You return me to Paradise?" He said, "Yes." [Al-Suddī from Ibn ʿAbbās]
3. He said: "O Allah, there is no deity except You. Glory be to You and praise. O Lord, I have wronged myself, so forgive me, for You are the best of forgivers. O Allah, there is no deity except You. Glory be to You and praise. O Lord, I have wronged myself, so have mercy on me, for You are the best of those who show mercy. O Allah, there is no deity except You. Glory be to You and praise. O Lord, I have wronged myself, so accept my repentance, for You are the Most Repentant, the Most Merciful." [Ibn Abī Najīḥ from Mujāhid] 

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Other similar expressions of apology close in meaning to this have been reported as well.

What are the words that Adam received from his Lord?