Preserve knowledge by writing it

It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that he used to say to his sons: "Preserve knowledge by writing it down."
Some of the people of Basra also narrated it as marfu' (as a saying of the Prophet (peace and blessings be upon him)).

It is narrated from Sayyiduna Abdullah bin Amr bin al-As (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Secure knowledge." I said: "What is meant by securing it?" He (peace and blessings be upon him) said: "Writing it."

It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both): When the Messenger of Allah (peace and blessings be upon him) passed away, I said to a man of the Ansar: "Come, let us ask the Companions of the Messenger of Allah (peace and blessings be upon him) (for knowledge), for today they are present in large numbers." He said: "How strange you are, O Ibn Abbas! Do you think that people will need you (for knowledge) while among the people there are eminent Companions of the Messenger of Allah (peace and blessings be upon him)?" He said: So I left that, and devoted myself to asking the Companions. If I learned that a certain man had a hadith, I would reach his door at midday; I would make my cloak a pillow and lie at his door while the wind blew dust over me. Then, when he came out and saw me, he would say: "O cousin of the Messenger of Allah (peace and blessings be upon him), what has brought you here? Why did you not send word to me, so that I would come to you myself?" I would say: "No, I have more right to come to you." Then I would ask him about the hadith. (Ibn Abbas said:) That Ansari man lived long enough to see me when people had gathered around me (for knowledge), and he said: "This young man was wiser than me."
This hadith is sahih (authentic) on the condition of Imam Bukhari, and it is a fundamental proof regarding seeking hadith and honouring the muhaddith.