Taking Refuge in the Dhamma Friends, having heard in many a Dhamma talk references being made to the permanence of the Dhamma as refuge, I am looking for suttas in the Pali Canon evoking that very theme of permanence of the Dhamma.

Thank you for your much appreciated help.
The Dhamma is described as timeless (akāliko).

From the Pali glossary:


  akāliko:
      Timeless; unconditioned by time or season.


From SN 55.22:


  "He/she is endowed with verified confidence in the Dhamma: 'The Dhamma
  is well-expounded by the Blessed One, to be seen here &amp; now, timeless,
  inviting verification, pertinent, to be realized by the wise for
  themselves.'


From AN 6.47:


  "... the Dhamma is visible in the here-&amp;-now, timeless, inviting
  verification, pertinent, to be realized by the wise for themselves."


From AN 3.40:


  Now, the Dhamma is well-taught by the Blessed One, to be seen here &amp;
  now, timeless, inviting all to come &amp; see, pertinent, to be seen
  by the wise for themselves. There are fellow practitioners of the
  chaste life who dwell knowing &amp; seeing it.


You can also find this in AN 11.11, AN 11.12, AN 5.179, AN 10.92 and AN 3.70.

From this essay by Ajahn Sumedo:


  The second refuge is in the Dhamma, in ultimate truth or ultimate
  reality. Dhamma is impersonal; we don’t in any way try to personify it
  to make it any kind of personal deity. When we chant in Pali the verse
  on Dhamma, we say it is ‘sanditthiko akaliko ehipassiko opanayiko
  paccattam veditabbo vinnuhi’. As Dhamma has no personal attributes, we
  can’t even say it is good or bad or anything that has any superlative
  or comparative quality; it is beyond the dualistic conceptions of
  mind.
  
  So when we describe Dhamma or give an impression of it, we do it
  through words such as ‘sanditthiko’, which means immanent,
  here-and-now. That brings us back into the present; we feel a sense of
  immediacy, of now. You may think that Dhamma is some kind of thing
  that is ‘out there’, something you have to find elsewhere, but
  sanditthikodhamma means that it is immanent, here-and-now.
  
  Akalikadhamma means that Dhamma is not bound by any time condition.
  The word akala means timeless. Our conceptual mind can’t conceive of
  anything that is timeless, because our conceptions and perceptions are
  time-based conditions, but what we can say is that Dhamma is akala,
  not bound by time.
  
  Ehipassikadhamma means to come and see, to turn towards or go to the
  Dhamma. It means to look, to be aware. It is not that we pray to the
  Dhamma to come, or wait for it to tap us on the shoulder; we have to
  put forth effort. It is like Christ’s saying, ‘Knock on the door and
  it shall be opened.’ Ehipassiko means that we have to put forward that
  effort, to turn towards that truth.
  
  Opanayiko means leading inwards, towards the peace within the mind.
  Dhamma doesn’t take us into fascination, into excitement, romance and
  adventure, but leads to Nibbana, to calm, to silence.
  
  Paccattam veditabbo vinnuhi means that we can only know Dhamma through
  direct experience. It is like the taste of honey — if someone else
  tastes it, we still don’t know its flavour. We may know the chemical
  formula or be able to recite all the great poetry ever written about
  honey, but only when we taste it for ourselves do we really know what
  it is like. It is the same with Dhamma: we have to taste it, we have
  to know it directly.
  
  Taking refuge in Dhamma is taking another safe refuge. It is not
  taking refuge in philosophy or intellectual concepts, in theories, in
  ideas, in doctrines or beliefs of any sort. It is not taking refuge in
  a belief in Dhamma, or a belief in God or in some kind of force in
  outer space or something beyond or something separate, something that
  we have to find sometime later. The descriptions of the Dhamma keep us
  in the present, in the here-and-now, unbound by time. Taking refuge is
  an immediate immanent reflection in the mind, it is not just repeating
  ‘Dhammam Saranam gacchami’ like a parrot, thinking, ‘Buddhists say
  this so I have to say it.’ We turn towards the Dhamma, we are aware
  now, take refuge in Dhamma, now as an immediate action, an immediate
  reflection of being the Dhamma, being that very truth.