ASK(-E/-A) ~ ash(es)

impression of Iron Age cremation (source)

varieties of burying ashes in mound: 1. loose in rectangular pit; 2. in urn; 3. in cloth or leather; 4. only covered by mound (illustration in brochure about Urnfields by Oermuseum Sept. '21)

some cognates
as - Dutch, Afrikaans
ash(es) - English
Asche - German
aske - Danish, Norse
aska - Swedish, Icelandic
jiske - Frisian*
āsa - Sanskrit
ačiun - Armenian
hassa - Hittite

(* Ironically, the New-Frisian variety is more divergent from Old-Frisian than the other NW-European cognates. There are more examples of this peculiar phenomenon.)

varieties in Oera Linda
ASKE - 2f
ASK - 5d, 7b
ASKA - 14d

fragments

2f. Frya’s Tex (p. 39)
AFTERNÉI HJARA ASKE FIFTICH FÍT ANDA GRVND TO DÀLVANE TILTHJU THÉR NÉNEN GÀRS.HÀLM VP WAXA NI MÉI. HWAND ALDULKERA GÀRS SKOLDE JVW DJAROSTA KVIK DÉJA.
Thereafter, bury their* ashes fifty feet deep, so not a single blade of grass would grow into them, for such grass would kill your most precious cattle. (*anyone who robs another of his freedom, and his mother)

5d. Punishments for Evildoers (p. 75)
THA STJVRAR SKOLDON SIN MÀM ÀND AL SINA SIBBA NÉI EN FÉR É.LAND MOTA BRÀNGA AND THÉR SIN ASK FORSTUVA TILTHJU.R HÍR NÉN FENINIGE KRÛDON FON WAXA NE MÜGE.
The steersmen must take his* mother and all his relatives to a distant island and there scatter his ashes, so that no poisonous herbs may sprout from them here. (*someone so evil as to betray us to the enemy by revealing paths and passages that lead to our places of refuge)

7b. How Aldland Sank, ca. 2190 BCE (p. 84)
WALDA BÀRNADON THÉR.THRVCH ÀFTER EKKORUM ÀND THÁ WIND DÁNA WÉI KÉM. THÁ WÁJADON VSA LANDA FVL ASK.
As a result, forests burned one after the other, and when Wind came from there, our lands were covered with ashes.

14d. Alexander the King (p. 170)
AS HJA HÉRADON THÀT HJA MITH MOSTE STATON HJA THA TIMBER HLOTHA ANE BRÔND. THÉRTHRVCH WRDE VS ÉLE THORP ANDA ASKA LÉID.
When they heard that they had to join, they set the lumberyards ablaze, which reduced our whole village to ash.