What all Hindu scriptures advocate The Golden Rule? And what is the oldest Hindu scripture to advocate it?

Question

According to Wikipedia, The Golden Rule, treat others as you treat yourself, is common to most world religions. Here are a couple of references from Hindu scripture:

One should never do that to another which one regards as injurious to one’s own self. This, in brief, is the rule of dharma. Other behavior is due to selfish desires.

— Brihaspati, Mahabharata (Anusasana Parva, Section CXIII, Verse 8)

श्रूयतां धर्मसर्वस्वं श्रुत्वा चाप्यवधार्यताम्।
आत्मनः प्रतिकूलानि परेषां न समाचरेत्।।

If the entire Dharma can be said in a few words, then it is—that which is unfavorable to us, do not do that to others.

— Padmapuraana, shrushti 19/357–358

What other/all Hindu scriptures advocate this Golden Rule?

What is the oldest Hindu scripture to advocate it? Do the Vedas (saṃhitas) mention this rule?

Answer 1

I have not found any direct reference in Veda Samhita upto now. However there can be various verses which can give indirect meaning of Golden Rule. For eg. This verse from YajurVeda:

यस्तु सर्वाणि भूतान्यात्मन्येवानुपश्यति ।
सर्वभूतेषु चात्मानं ततो न विजुगुप्सते ॥
यस्मिन्सर्वाणि भूतान्यात्मैवाभूद्विजानतः ।
तत्र को मोहः कः शोक एकत्वमनुपश्यतः ॥ (Yajurveda 40.6,7)

He who sees all beings in his own self and his own self in all beings does not suffer from any repulsion by that experience. He who has known that all beings have become one with his own self, and he who has seen the oneness of existence, what sorrow and what delusion can overwhelm him?

If one sees everyone as his self certainly he doesn't do that behaviour to him which he doesn't like himself. Thus, this can become indirect reference to Golden Rule from Veda Samhita itself.

Answer 2

There are many places in Mahabharata where the Golden Rule is advocated.

Bhishma’s morality

Bhishma said, ‘Knowing how painful it is to himself, a person should never do that to others which he dislikes when done to him by others.’

Mahabharata Santi Parva Section CCLX

Vidura on virtue

Vidura said, ‘Study of the various scriptures, asceticism, gift, faith, performance of sacrifices, forgiveness, sincerity of disposition, compassion, truth, self-restraint, these constitute possessions of Virtue. Do thou adopt Virtue. Let not, thy heart ever turn away from it. Both Virtue and Profit have their roots in these. I think that all these are capable of being included in one term. It is upon Virtue that all the worlds depend (for their existence). It is by Virtue that the gods attained to their position of superiority. It is upon Virtue that Profit or Wealth rests. Virtue, O king, is foremost in point of merit. Profit is said to be middling. Desire, it is said by the wise, is the lowest of the three. For this reason, one should live with restrained soul, giving his attention to virtue most. One should also behave towards all creatures as he should towards himself.

Mahabharata Santi Parva Section CLXVII

Vidura on how to treat others

That which is antagonistic to one’s own self, should never be applied in respect of another.

[Mahabharata Udyoga Parva, Section 39]

Answer 3

This is addressed in the Gita in several places. Gita 13.27-28 says (Swami Gambhirananda translator):

He sees who sees the supreme Lord as existing equally in all beings, and as the Imperishable among the perishable.

Since by seeing equally God who is present alike everywhere he does not injure the Self by the Self, therefore he attains the supreme Goal.

And in Gita 6.9:

He excels who has sameness of view with regard to a benefactor, a friend, a foe, a neutral, an arbiter, the hateful, a relative, good people and even sinners.

Swami Vivekananda comments on verse 13.28 above in his Complete Works V3, p 425 (Available here under the heading 'Lectures from Colombo to Almora', sub-heading 'The Vedanta' - http://www.advaitaashrama.org/cw/content.php):

In the second place, Advaita and Advaita alone explains morality. Every religion preaches that the essence of all morality is to do good to others. And why? Be unselfish. And why should I? Some God has said it? He is not for me. Some texts have declared it? Let them; that is nothing to me; let them all tell it. And if they do, what is it to me? Each one for himself, and somebody take the hindermost — that is all the morality in the world, at least with many. What is the reason that I should be moral? You cannot explain it except when you come to know the truth as given in the Gita: "He who sees everyone in himself, and himself in everyone, thus seeing the same God living in all, he, the sage, no more kills the Self by the self." Know through Advaita that whomsoever you hurt, you hurt yourself; they are all you. Whether you know it or not, through all hands you work, through all feet you move, you are the king enjoying in the palace, you are the beggar leading that miserable existence in the street; you are in the ignorant as well as in the learned, you are in the man who is weak, and you are in the strong; know this and be sympathetic. And that is why we must not hurt others. That is why I do not even care whether I have to starve, because there will be millions of mouths eating at the same time, and they are all mine. Therefore I should not care what becomes of me and mine, for the whole universe is mine, I am enjoying all the bliss at the same time; and who can kill me or the universe? Herein is morality. Here, in Advaita alone, is morality explained. The others teach it but cannot give you its reason. Then, so far about explanation.