Context
I am practicing my biblical Hebrew by translating the weekly Parshah. As resources, I have the Brown-Driver-Briggs (BDB) Lexicon (coded with Strong's concordance numbers) and Gesenius' Grammar - specifically the edition expanded and edited by Kautzsch. I am using the Stone edition Chumash, which includes both vowelized Hebrew and English translation. After translating a sentence myself, I then cross-check to see the differences between my translation and the Stone translation, note which ones are obvious mistakes on my part and then make notes on the more ambiguous differences to ask my Rabbi (or here) later. This question pertains to Lev 6:1, and specifically the opening word of the Hebrew: וַיְדַבֵר (translated by Stone as "spoke" in the clause: :וַיְדַבֵר יהוה אל–משה לֵאמְֹר - "Hashem spoke to Moses, saying:").
Actual Question(s)
What does the vav-consecutive in וַיְדַבֵר tell us about the tense of the word? Am I misreading the prefix here as the vav-consecutive?
What My Sources Say
I am trying to better understand the vav-consecutive as a grammatical tool. In Gesenius, §49 (a), the vav-consecutive is described as setting up a series of sequential events. In this same section, Gesenius notes that if the first verb of the sequence -- I assume this means the verb attached to the pregnant vav -- is in the perfect tense, the rest are in the imperfect and the entire sequence represents a series of past events. For a chain of future events, the converse is true: the first verb is imperfect and the rest of the verbs are perfect.
There is only one other verb in this clause, לֵאמְֹר, and BDB states that it is "especially infinite, after וַיְדַבֵר (p. 55-56, entry 559.1), which is helpful for translating this sentence, but not super helpful for understanding the underlying grammatical structure in question. However, יְדַבֵר is stated as being in the imperfect by BDB (p. 180, sec 1696). This would initially make me think to translate this sentence in the future tense:
"Hashem will speak to Moses, to say:"
However, this seems intuitively not correct. What am I missing here? There is another entry for דַבֵר in the same section cited above that states it takes the imperative. But this also seems like a weird translation to me.
Any help or guidance to sources that will explain this to me (even citations within Gesenius I may be missing) would be helpful. Thank you!