وَلْيَكُنْ فِي خَاصَّةِ مَا تُخْلِصُ بِهِ لِلَّهِ دِينَكَ: إِقَامَةُ فَرَائِضِهِ الَّتي هِيَ لَهُ خَاصَّةً، فَأَعْطِ اللهَ مِن بَدَنِكَ فِي لَيْلِكَ وَنَهَارِكَ، وَوَفِّ مَا تَقَرَّبْتَ بِهِ إِلَى اللهِ مِنْ ذلِكَ كَامِلًا غَيْرَ مَثْلُومٍ وَلَا مَنْقُوصٍ، بَالِغاً مِنْ بَدَنِكَ مَا بَلَغَ.
(Communion with Allāh:) The particular thing by which you should purify your religion for Allāh should be the fulfilment of those obligations which are especially for Him. Therefore, devote to Allāh some of your physical activity during the night and the day, and whatever (worship) you perform for seeking nearness to Allāh should be complete, without defect or deficiency, whatsoever physical exertion it may involve.