What does John 4:31 mean?

The disciples had gone into town to buy food (John 4:8). Jesus had stayed behind at the well outside of town to rest (John 4:6). Naturally, when the disciples returned, their primary concern was Jesus' hunger and thirst. That the men were "urging" Jesus to eat suggests that He was not accepting whatever food they had offered. Jesus, as was typical, takes the opportunity to make an everyday event into a profound spiritual lesson.

Virtually all English translations of John 4:31 use the word "meanwhile," or "meantime." This comes from an entire phrase in Greek, en tō metaxy. This explicitly means that there has been a passage of time. The prior verses described the Samaritan woman returning to town, telling others about Christ, and asking them to see Him. This verse implies that while all of this was going on, the disciples are trying to get Jesus to eat, and He is not interested in physical food. It's entirely possible He was waiting for the events described in verses 39–42, to make His upcoming lesson more meaningful.

The term "Rabbi" means "teacher," and was a title of respect. This was the same term used even by the Pharisee Nicodemus in reference to Jesus (John 3:1–2).