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:18:88 –

But as for one who believes and does righteousness, he will have a reward of Paradise, and we will speak to him from our command with ease."  

But as for him who believes and acts righteously, he shall have the fairest reward, namely, Paradise (the annexation construction ˹jazā’u l-husnā, ‘the fairest reward’˺ is explicative; a variant reading has jazā’an alhusnā, ‘˹he shall have˺ as a requital that which is fairest’; al-Farrā’ said that this accusative ˹reading of jazā’an˺ is ˹intended˺ as an explanation ˹of the nature of the requital˺ by way of attribution ˹to ‘that which is fairest’˺; and we shall speak to him mildly in our command’, that is to say, we shall command him with what he will find easy ˹to bear˺.
القرآن:١٨:٨٨ –

وَأَمَّا مَنْ آمَنَ وَعَمِلَ صَالِحًا فَلَهُ جَزَاءً الْحُسْنَىٰ ۖ وَسَنَقُولُ لَهُ مِنْ أَمْرِنَا يُسْرًا  

{وأما من آمن وعمل صالحا فله جزاء الحسنى} أي الجنة والإضافة للبيان وفي قراءة بنصب جزاء وتنوينه قال الفراء: ونصبه على التفسير أي لجهة النسبة {وسنقول له من أمرنا يُسرا} أي نأمره بما سهل عليه.