Think of something you know well enough to teach.
Now try to work out where you got it. Not the book, the lecture or the video. The whole line. Who taught the person who taught you, and who taught them, back as far as the chain will run before it goes dark.
You will not get far. Almost nobody can. We hold knowledge the way we hold a coat we picked up at a party, with only the vaguest sense of whose it was.
The Islamic scholarly tradition took the opposite view, to an extent that can look obsessive.
Every hadith, every recorded saying of the Prophet, peace and blessings be upon him, carries its silsila: a chain of names running back through the centuries from the scholar who wrote it down to the companion who heard the words spoken. Not as decoration. As part of the claim.
Set that beside how we hold knowledge now and the contrast is uncomfortable.
The mathematics you were taught at school passed through Indian mathematicians, Islamic scholars and European translators before it reached your textbook, and the textbook mentioned none of them.
Everything is inherited. Nothing is original. The chain is always there. We have simply stopped keeping the register.
In the Qur'anic account of the creation of man, God announces to the angels that He is placing a khalifa on the earth, a trustee. The angels object, reasonably enough. They have seen what this creature does: bloodshed and corruption. Why make it?
God does not argue with them. He demonstrates. He teaches Adam the names of all things, then turns to the angels: tell Me the names of these, if you are truthful.
They cannot. And their reply is one of the most striking sentences in the book: Glory be to You. We have no knowledge except what You have taught us.
Then Adam is asked, and Adam names them.
Three things follow, and the third is the one that should unsettle you.
First, knowledge here is not discovered. It is given. Second, knowledge is what qualifies humanity for the job. Third, and this is the part that does the work: knowledge is a trust.
The Arabic is amana. That which is entrusted. It appears in a verse with an alarming implication: the trust was offered to the heavens, the earth and the mountains, and they declined it and were afraid of it, and man took it up.
If that is what knowledge is, then it is not property.
It is not something you own, hoard, sit on, price up, or hold back to keep an advantage over the person who might use it better. It is something placed in your care, for a while, with the expectation that you will preserve it, extend it if you can, and hand it on intact.
You are a link. That is the whole of your role. Links do not own the chain.
So the register matters after all.
Not out of politeness to the dead, and not so that anyone can total up who owes whom. It matters because knowing you received something is the only reliable way of remembering that you are supposed to pass it on.
Break the chain and the trust is betrayed. Keep it, and you have done the one job you were given.