By following the Buddha's Path, when will I realize that I am free from rebirth and suffering? Is there any indication or sign ? Does one knows it at one's death bed?
The king said, “Is there anyone who is not reborn after death?”
“Yes there is. The one who has no defilements is not
reborn after death; the one who has defilements is reborn.”
“Will you be reborn?”
“If I die with attachment in my mind, yes; but if not, no.”
He who is reborn, Nàgasena, is he the same person or another?”
“Neither the same nor another.
“Is the man who will not be reborn aware of the fact?”
“Yes, O king.”
“How does he know it?”
“By the cessation of all that is cause or condition of rebirth. As a farmer who does not plough or sow or reap would know that his granary is not getting filled up.”
What is it, Nàgasena, that is reborn?”
“Mind and matter (namarupa).”
“Is it this very mind and matter that is reborn?”
“No, it is not, but by this mind and matter deeds are done and because of those deeds another mind and matter is reborn; but that mind and matter is not thereby released from the results of its previous deeds.
“Does he who will not be reborn feel any painful feeling?”
“He may feel physical pain, O king, but not mental pain.”
“If he feels painful feelings then why doesn’t he just die and attain the extinction of grasping, and put an end to suffering?”
“The arahant has no fondness for or aversion to life...
“Will you, Nàgasena, be reborn?”
“What is the use of asking that question again? Have I not already told you that if I die with attachment in my mind I shall be reborn, if not I shall not.”
“Would he who is about to be reborn know it?”
“Yes he would, just as a farmer who puts seed into the ground, seeing it rain well, would know that a crop will be produced.”
So, do you feel that you still have attachments, mental or emotional? That's how you know.
As soon as you become an Arahant. In other words, when you attain the undying.
In the training that I've received (Soto Zen), both rebirth and being free from it are considered completely metaphorical. As such, it's something that changes about your experience of your current life, when you break yourself of the cyclical behavior of clinging to your thoughts as though they are real.
By following the Buddha's Path, liberation from birth is realized when your past lives are experienced, known, seen, looked into and the answer to the question "Why was I born?" is answered.
Only then, the cause of birth is known, its cessation is known and birth is: removed, removed.
As soon as you become an Arahant.
In other words, when you fully realize the
Three marks of existence.
No personal viewpoint.
Nature of without cravings.
Elimination of the 3 roots of carving.