O you whose nature is unyielding and whose heart is inclined towards his nature: think of the purpose for which you were created, and what is it that Allah made incumbent upon you. If you wish to ride the stallion that is your soul, then you must tame it, and counteract the effect of your mercurial nature, so that you can harness it for proper use. Look for the dawn of reward during the nights, and pour out the intoxicant of your desires, is that you do not get caught by the One in authority [Allah].
The water of your nature is brine, whereas the water of your heart is sweet, your intellect standing between the two as a barrier, just as al-Khidr’s firm stance. So be like Musa, peace be upon him, and do not abandon your self-discipline until you arrive at the meeting point of the two oceans. Stand on the leg of patience [praying all night] even if standing is too wearisome, as it is better than sitting down. O you who has been asleep all night long, the company has already left, and the sun of old-age is upon you and yet your sleep does not end. If you had been awake in the last part of the night, you would have seen how the road of the pious slaves is crowded and had you gone to drink from the well of Madiyan, you would have found many people quenching their thirst from it.
How bright is the night of the pious, which is spent by them in worship; they remain standing, leaning on the pillar of their fear of Allah, as they approach the road of longing to their Lord, as the night covers them under its roof. When they sigh [out of their love of Allah] they are more adoring than a lover, and when they mourn [from fearing Allah and their love towards Him] they are more eloquent than al-Khansa [the female poet].
They found the right path, and hence walked on it; “Indeed, those who have said, ‘Our Lord is Allah’ and then remained on a right course.” (al-Fusslat 41:30)
But how far behind you are from even catching the traces of dust left by their caravan trail! Their hope does not stretch far at all, and their houses are more austere than a grave, their sleep is rare and their conditions are softer than a breeze. For them, spending the night in prayer is more joyful, than sleeping at night after waking up. Whenever they recite a Surah from the Qur’an they reflect on it as passionately as Yaqub, peace be upon him, when he caught a waft of Yusuf’s aroma.
Be present during the last part of the night, and join the worshippers long enough to witness the lavishing of the King’s gifts upon them, because even if you were not amongst their party, you might at least receive a portion of what they received, “And when [other] relatives and orphans and the needy are present at the [time of] division, then provide for them [something] out of it [i.e. the estate]” (al-Nisa 4:8) When you exhale, giving out breaths of regret, they rise and form clouds, to patter upon you drops of forgiveness. And if you shed a tear on the cheek of repentance, you will give life to your barren heart.
Seeds of Admonishment and Reform by Imam Ibn Jawzi pages 150-152