Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:23:118 –

And, ˹O Muhammad˺, say, "My Lord, forgive and have mercy, and You are the best of the merciful."  

And say: ‘My Lord, forgive and have mercy, on believers — ˹this˺ ‘mercy’ adds to the ‘forgiveness’ ˹in terms of God’s grace˺ — and You are the best of the merciful’, the most excellent of those who have mercy. Medinese, consisting of 62 or 64 verses.
القرآن:٢٣:١١٨ –

وَقُلْ رَبِّ اغْفِرْ وَارْحَمْ وَأَنْتَ خَيْرُ الرَّاحِمِينَ  

{وقل رب اغفر وارحم} المؤمنين في الرحمة زيادة عن المغفرة {وأنت خير الراحمين} أفضل راحم.