Friend who is the same in happiness and sorrow Sigalovada Sutta: The Discourse to Sigala
The Layperson's Code of Discipline includes,

&quot;These four, young householder, should be understood as warm-hearted friends:
(1) he who is a helpmate,
(2) he who is the same in happiness and sorrow,
(3) he who gives good counsel,
(4) he who sympathises.

And

(2) &quot;In four ways, young householder, should one who is the same in happiness and sorrow be understood as a warm-hearted friend:
(i) he reveals his secrets,
(ii) he conceals one's own secrets,
(iii) in misfortune he does not forsake one,
(iv) his life even he sacrifices for one's sake.

I thought I could guess the correlation between being &quot;warm-hearted&quot; and being &quot;the same in happiness and sorrow&quot;; but, my guesses didn't really match any of the four ways given, except for the 3rd way (i.e. perhaps I understand why &quot;being the same&quot; includes &quot;does not forsake&quot;, but don't understand the others). So:

Does &quot;being the same in happiness and sorrow&quot; mean Upekkha?
Does &quot;warm-hearted friend&quot; mean Kalyana Mittas?
Why are revealing and concealing secrets mentioned? What kinds of secrets? What do &quot;secrets&quot; have to do with being &quot;the same in happiness and sorrow&quot;?
The last item, &quot;his life even he sacrifices for one's sake&quot; -- can that be reconciled with the answers to the question, How to be compassionate to a friend in need? Those answers seem to suggest that you can only help yourself.
In indo-european folklore the common expression "the same in happiness and sorrow" usually means one who stays a loyal friend not only in happy times but also in times of trouble, when having all responsibilities of a true friend could be taxing. This corresponds with #3 on the list, "in misfortune he does not forsake one".

By extension, "the same in happiness and sorrow" means one who is not seeking a benefit for oneself from the friendship, but sincerely gives oneself away to the friend. This is where the other three come from:


  (i) he reveals his secrets,
  (ii) he conceals one's own secrets,
  ...
  (iv) his life even he sacrifices for one's sake.


"Warm-hearted" means a friend whose relationship of trust and commitment comes from the heart, is unforced and natural. Such friend would not have to make an effort to "sacrifice his life for one's sake", it would come naturally.

Altogether, the above is not to be understood literally, but is meant to portray the attitude of uncalculated selfless fondness, almost love, as the perfection of friendship.