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 the taking away of knowledge is that the people of knowledge come to an end. Beware! Protect yourselves from extremism, excessive scrutiny (over-analysis), and inventing new acts of worship, and hold firmly to the ancient way. (That is, adhere to the way of the Messenger of Allah, peace and blessings be upon him, and his companions, may Allah be pleased with them all.)