Diamond Sutra, chapter 14

“Subhuti, in a previous life I met Dipankara Buddha, I had made many offerings and been very virtuous. If someone is able to receive, study, and practice this Sutra in a later, more distant age, then the happiness and merit brought about by this virtuous act would be much greater than that which I brought about by my previous virtue. In fact, such happiness and merit is incomparable. I know this might be hard to believe. Subhuti, you should know that the meaning of this Sutra is beyond understanding.”

It’s said that Siddhartha Gautama, the one we call the Buddha, wasn’t the first Buddha. They say that he studied with previous Buddhas from other ages in prior lives. That’s what this section is referencing. There are many stories about the Buddha doing good things in previous lives, sometimes as a human and sometimes as an animal. These are called Jataka tales and bear some similarity to fables in the western world. They are stories designed to teach children lessons about things like kindness, paying attention, etc. The Buddha in this section is saying that the merit of studying the Diamond Sutra is greater than merit that he generated in his previous lives.

Diamond Sutra, chapter 10

The Buddha continued, “When I was in a previous life did I receive any teaching or attain any degree of self-control that later helped me become a Buddha?”
“No. You didn’t receive any teaching or attain any degree of self-control in a previous life that helped you become a Buddha.”
The Buddha said, “A disciple should develop a mind which is not dependent on the senses or mental conceptions. A disciple should develop a mind that doesn’t rely on anything.”
“So the minds of disciples should be purified. They should use their minds naturally, without being constrained by preconceived notions that arise from the senses.”

The Buddha is repeated the point that Awakening doesn’t come from someone else, it comes from within. It’s been said that in a previous life the Buddha learned from someone named Dipankara. Even if this is true, that doesn’t mean that Dipankara led the Buddha to Awakening. Dipankara only pointed the way, just as teachers do for the rest of us.
The Buddha goes on to say that our minds shouldn’t be imprisoned by having to rely on our preconceived notions. Nor should they be imprisoned by delusions arising from our senses which, if we are honest with ourselves, have a tendency to deceive us sometimes. A disciple should strive to interact with the world without attaching to any particular paradigm.