The 'asl is that nothing is wājib upon Allāh. Rather, His rewarding you is His fadl and His punishment is His justice. Allāh says in the Qurān
He is not questioned about what He does
Qurān 21:23
Everything Allāh has sanctioned is for the betterment of His slaves in this world and the next. Allāh is free of His slaves and does not need them. The obedience of the ones who obey Him does not benefit Him, and the disobedience of the ones who disobey Him does not harm Him.
الأَْصْل أَنَّهُ لاَ يَجِبُ عَلَى اللَّهِ شَيْءٌ، بَل الثَّوَابُ فَضْلُهُ وَالْعِقَابُ عَدْلُهُ {لاَ يُسْأَل عَمَّا يَفْعَل (1) } وَالتَّكَالِيفُ كُلُّهَا رَاجِعَةٌ إِلَى مَصَالِحِ الْعِبَادِ فِي دُنْيَاهُمْ وَأُخْرَاهُمْ وَاللَّهُ غَنِيٌّ عَنْ عِبَادَةِ الْكُل، لاَ تَنْفَعُهُ طَاعَةُ الطَّائِعِينَ، وَلاَ تَضُرُّهُ مَعْصِيَةُ الْعَاصِينَ (2)
Kuwaiti Encyclopedia of Fiqh