TofG.....Light and fire as universal topoi for knowledge, purity, goodness and by association deity, are as old as man.
I find the literary nature of these stories fascinating. there was an active free creative process in those early years. I.e. until institutional conformity froze certain versions of the legends into canon.
The recurring reuse of motif and metaphor is another aspect of this. Fire/water, Light/dark, Crop sowing/harvesting, tree fertility/barrenness, water flowing/parting. spirit/bird wings etc. Leolaia did a neat thread years ago demonstrating how parables were reused as narrative and narrative as parable, they were two sides of the same coin.
Jesus and the Fig Tree.
In this case a corollary use of the imagery is seen in Matt 3:11 where this revisor of Mark takes the line, "I have been baptizing with water, he will baptize you with holy spirit" and adds "and fire". This then serves as segue for another parable featuring fire as a method of cleansing the threshing floor. Luke follows that pattern. It's impossible to say if there is a direct link between Matt's baptism with 'fire' and the baptism scene accompanied by fire but they come from the same milieu of popular topoi.