How can the soundest narrations in Sahih Al-Bukhari be distinguished, given the existence of multiple narrations for the same Hadith, such as the Hadith "Deeds are by intentions," and does Al-Bukhari's statement: "So-and-so bin So-and-so followed him" mean that the followed narration is the soundest?

The way to identify the strongest narrations is by consulting the commentaries, especially "Fath al-Bari" by Ibn Hajar. Al-Bukhari prioritizes, postpones, and repeats for jurisprudential, hadith (definition)-related, or literary purposes, not merely for authenticity. He rarely presents a hadith in two places with the same chain of narration and the same wording. He may narrate it from one Companion and then from another to remove any element of rarity from the hadith.

As for Al-Bukhari's statement "So-and-so followed him," it does not mean that the follow-up is stronger or weaker; rather, it signifies participation in the narration. Its strength or weakness is determined by the precision of the followers. Follow-up means a narrator sharing the narration of a hadith with another. It can be complete (sharing from the beginning of the chain of narration) or partial (sharing during the chain of narration).