It is narrated from Abu Qilabah that Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: Acquire knowledge before it is taken away, and its being taken away means that the people of knowledge will be taken away. Hold fast to knowledge (because) none of you knows when he will be in need of it, or when someone who possesses knowledge will be needed. You will find many people who will think that they are calling towards the Book of Allah, while in fact they will have cast it behind their backs. Hold firmly to knowledge and beware of inventing new acts of worship (bid'ah), avoid exaggeration, refrain from unnecessary depth and intricacy, and follow the footsteps of the predecessors.