Sheikh al-Alawi, may Allah be pleased with him, when sitting in the Zawiya, would always have in front of him a tray with a large kettle filled with tea and several glasses, so he could serve tea to the many visitors who would come and sit with him throughout the day.
One day he was sitting with the fuqara. He filled up one of the glasses with tea up to the brim. He asked the fuqara, 'is it possible for this glass to be filled any further?'
'Of course not', they answered. 'It is full.'
The Sheikh then took a single rose petal and laid it on top of the tea. None of the liquid spilled. The glass was filled further.
Thus the scholar of the outward sciences, who may appear to have mastered all that there is to learn, can further be adorned with the science of Tasawwuf, and illuminate his knowledge with the Light of the Knowledge of Allah.