The word for burying (וַיִּקְבֹּ֨ר) is an imperfect. But, with special pointing, it becomes a "waw consecutive imperfect." A w.c.imf. inverts the normal aspect/tense of the verb (from future to past).
How do you know when it's a w.c.imf.? It has a waw + patach (vowel) + dagesh forte. Without this pattern it's just a plain old imperfect.
I learned this as a "Waw consecutive imperfect." Other grammarians refer to it as converted imperfect or inverted future. Cf. JM:
§ 47. Inverted Future וַיִּקְטֹל
47a The inverted future, e.g. וַיִּקְטֹל and he killed, has a strong
Waw, that is to say, a Waw which has vowel a that adds some force
(like that of the definite article [§ 35 b] and that of the
interrogative pronoun מה [§ 37 c]) to the following consonant, which,
as a consequence, is doubled. The doubling is omitted in, e.g.
וַיְקַטֵּל (§ 18 m)1.
With the Waw inversive the verb form undergoes two changes in
accordance with the phonetic laws: 1) the final vowel reflects earlier
shortening as in the jussive (§ 46 a); 2) the stress falls on the
penultimate syllable, and as a consequence, the post-stress, ultima
vowel becomes short2.
(Paul Joüon and T. Muraoka, A Grammar of Biblical Hebrew, vol. 27 of
Subsidia biblica. Accordance electronic ed. (Roma: Pontificio istituto
biblico, 2006), 128-129.)
