John Gill Commentary John 1:37

"And the two disciples heard him speak, and they followed Jesus." — John 1:37 (ASV)

And the two disciples heard him speak
The above words, and took notice of them; faith in Christ came by hearing them; they reached their hearts, and they found their affections, and the desires of their souls, to be after Christ:

and they followed Jesus ;
left their master, and went after him, in order to get some acquaintance with him, and receive some instructions from him.