It says pretty explicitly "He took in his hands, the fire", if he didn't know firebending, then how did he not get burnt?
Let's also not forget how he was thrown into the fiery furnace and survived
BUT the thing is is that Avraham is usually associated with Chesed, which represents water [see end of Tanya ch. 5], so what was he?
I was thinking perhaps the Avatar is mainly one element, but also has the power to use other elements, so perhaps one can say that here as well
So based on that, it would imply that Avraham was originally born in the water tribe, but, as the Avatar, learned firebending later.
The only thing, is that its also implied strongly that Moshe was a waterbender, as it says "I'll call him Moshe, because from the water I've drawn him", as well as his ability to split the sea, and bring forth water from the rock.
However, if we count the cycle of Avatars, given that Moshe is the 7th from Avraham [see Basi Legani 5710 and midrash there in beginning] then it doesn't seem to work, if both Avraham and Moshe were [mainly] waterbending Avatars, let's see.
So if we assume Avraham was originally a waterbender, because he represents Chesed, then it stands to reason that Yitzchak would be fire, because that's Gevurah, and given that the 4 elements go in the order of Hashem's name [see Likutei Torah Shlach] with:
air being Yud, Chochmah;
fire being first Hey, Binah;
water being Vav, Chesed [Z"a, hamshacha]
Earth/Dust being last Hey, Malchus
AND if we're going in the order of first water [Avraham, Chesed] then fire [Yitzchak, Gevurah] then the Avatar order is seemingly:
Avraham -- Water
Yitzchak -- Fire
Yaakov -- Air
Yehudah (king of brothers) [or another brother, not sure about this one] -- Earth
Kehos [again not sure who it would be in this generation, or if it skips etc...] -- Water
Amram [probably] -- Fire
Moshe -- Air
so then Moshe would be air! And even though there are several instances where its's implied that Moshe was a pretty big expert at airbending, such as when he flew to Italy with the angels in the clouds to get esrogim, as well as when he jumped to the top of Mount Nevo in one leap, or when he flew into outer space, above the stars to cause the plague of hail [see Rashi there], but still, based on the fact that his name represents water, it would stand to reason that he was mainly a waterbending Avatar, and just picked up airbending later in life, but the things is, if we assume Moshe is water, then let's work backwards:
Moshe -- Water
Amram -- Earth [if we assume same direction as before]
Kehos -- Air
Yehuda/other brother -- Fire
Yaakov -- Water
Yitzchak -- Earth
Avraham -- Air
then Avraham would be mainly an airbender, but what specific relation does Avraham have to air? Even though it says in the Maamer Gadol Yihyeh 5722 that the first Beis Hamikdash is the first hey, which has a revelation of Chochmah [Air, Yud], which also refers to Avraham who called Mount Moriah a "mountain" [similar to Binah], and the 2nd temple is the latter Hey, representing Malchus [element of Earth], which corresponds to Yitzchak who called it a field [Lasuach Basadeh, in the place of the temple], and assuming the first temple was from above to below, since it represented the service of Tzadikim [as mentioned in the beginning of the maamer there] and the second temple was from below to above, since it represented the idea of Baalei Teshuva, and given that Yitzchak is similar to the element of Earth in the sense that he could only stay in the holy land, but still, how would Avraham be related to air?
And where did he learn that firebending mentioned earlier, anyway?