To the seeker after Truth it is immaterial from where an idea comes. The source and development of an idea is a matter for the academic. In fact, in order to understand Truth, it is not necessary even to know whether the teaching comes from the Buddha, or from anyone else. What is essential is seeing the thing, understanding it. There is an important story in the Majjhima-nikāya (sutta no. 140) which illustrates this.
The Buddha once spent a night in a potter’s shed. In the same shed there was a young recluse who had arrived there earlier. They did not know each other. The Buddha observed the recluse, and thought to himself: ‘Pleasant are the ways of this young man. It would be good if I should ask about him’. So the Buddha asked him: ‘O bhikkhu, in whose name have you left home? Or who is your master? Or whose doctrine do you like?’
‘O friend,’ answered the young man, ‘there is the recluse Gotama, a Sakyan scion, who left the Sakya-family to become a recluse. There is high repute abroad of him that he is an Arahant, a Fully-Enlightened One. In the name of that Blessed One I have become a recluse. He is my Master, and I like his doctrine.’
‘Where does that Blessed One, the Arahant, the Fully-Enlightened One live at the present time?’
‘In the countries to the north, friend, there is a city called Sāvatthi. It is there that that Blessed One, the Arahant, the Fully-Enlightened One, is now living.’
‘Have you ever seen him, that Blessed One? Would you recognize him if you saw him?’
‘I have never seen that Blessed One. Nor should I recognize him if I saw him.’
The Buddha realized that it was in his name that this unknown young man had left home and become a recluse. But without divulging his own identity, he said: ‘O bhikkhu, I will teach you the doctrine. Listen and pay attention. I will speak.’
‘Very well, friend,’ said the young man in assent.
Then the Buddha delivered to this young man a most remarkable discourse explaining Truth … . It was only at the end of the discourse that this young recluse, whose name was Pukkusāti, realized that the person who spoke to him was the Buddha himself. So he got up, went before the Buddha, bowed down at the feet of the Master, and apologized to him for calling him ‘friend’ unknowingly. He then begged the Buddha to ordain him and admit him into the Order of the Sangha.
The Buddha asked him whether he had the alms-bowl and the robes ready. (A bhikkhu must have three robes and the alms-bowl for begging food.) When Pukkusāti replied in the negative, the Buddha said that the Tathāgatas would not ordain a person unless the alms-bowl and the robes were ready. So Pukkusāti went out in search of an alms-bowl and robes, but was unfortunately savaged by a cow and died.
Later, when this sad news reached the Buddha, he announced that Pukkusāti was a wise man, who had already seen Truth, and attained the penultimate stage in the realization of Nirvāṇa, and that he was born in a realm where he would become an Arahant and finally pass away, never to return to this world again.
From this story it is quite clear that when Pukkusāti listened to the Buddha and understood his teaching, he did not know who was speaking to him, or whose teaching it was. He saw Truth. If the medicine is good, the disease will be cured. It is not necessary to know who prepared it, or where it came from.