He who yearns neither desires food, nor finds pleasure in drink, nor is he quickly excitable, nor is he intimate even with his close friends, nor does he seek refuge in a house, nor does he dwell in a city, nor wear a garment nor take rest enough for his need.
He worships Allah night and day, hoping to reach the object of his yearning. He speaks to Him with the tongue of yearning, declaring what is in his innermost being.
This is as Allah said of Moses when he met his Lord:
وَعَجِلْتُ إِلَيْكَ رَبِّ لِتَرْضَى
I hastened to thee, my Lord, that Thou mightest be pleased. (20:84)
The Holy Prophet explained his state as follows: 'He neither ate, drank, slept nor desired any of that in his coming or going for forty days, out of his yearning for his Lord.'
When you enter the arena of yearning, then say takbir for yourself and your desires in this world. Bid farewell to all familiar things, and turn from all except the One you desire most.
Say the word Labbayk ('At Your service') between your life and your death: 'At Your service, O Allah, at Your service!' Then Allah will make your reward great. A person who yearns is like a drowning man: he is only concerned with being saved, and forgets every thing else.
Section 94, Misbah al-Shari'ah