In the Kindred Sayings (V, Maha-vagga, Book XII Kindred Sayings aout the Truths, Ch. V, part 6, Gross Darkness:
"Monks, there is a darkness of interstellar space, impenetrable gloom, such a murk of darkness as cannot enjoy the splendour of the moon and sun, though they be of such mighty magic power and majesty.'
In the rest of the Sutta, the Buddha talks about a greater and more fearsome darkness ~ Dukkha.
part of a rather similar thread here:Where in the canon?viewtopic.php?f=19&t=4544#p69238
BTW, samvega means:Samvega-vatthu:
'the sources of emotion', or of a sense of urgency, are 8:,birth, old age, disease, death, being 4; the suffering in the lower states of existence being the 5th; further, the misery of the past rooted in the cycle of rebirth, the misery of the future rooted in the cycle of rebirth, the misery of the present rooted in the search after food; Vis.M III..