The Way to Happiness, by Ibn Qayyim Al-Jawziyya, Ibn Badis
The joy of the heart is one of the greatest and most important things that help the servant to worship his Lord and Master, as He pleases. However, this joy has causes that the servant must strive to seek. Once he has succeeded in employing these means and Allah grants him the joy of the heart, he will be on a light from his Lord. Whoever achieves this will have earned the good of this world and the Hereafter. This is why Allah, Purity to Him and Most High be He, says: عَلَىٰ نُورٍ مِّن رَّبِّهِ"
