Sandra Glahn notes in a discussion on the importance of paying attention to narratival settings offers a detail that I had noticed before in the Gospel of John. She writes,
"Peter denies the Lord three times by a charcoal fire (John 18:17). Later, this setting provides Peter with a do-over in order to fully restore him. Three times Jesus gives Peter the opportunity to declare his love. And where does Jesus do so? By a charcoal fire (21:9). Through use of the charcoal-fire detail, readers can see what a grace-based ministry looks like. Interestingly, having experienced threefold grace following his threefold rejection, Peter would go on to exhort his flock to “grow in grace” (2 Pet 3:18)."
Sandra Glahn, "The Bible as Story: What the Literary Elements Reveal," Bibliotheca Sacra 178 (2021): 277.