The Samaritan woman LEFT her water jar and went away into town

[TonyChanYT]

John 4:

28 So the woman left her water jar and went away into town and said to the people, 29“Come, see a man who told me all that I ever did. Can this be the Christ?” 30They went out of the town and were coming to him.

Why did the Samaritan woman leave her waterpot?

Ellicott explained it logistically:

The waterpot left behind was a pledge of her return; and it is to us a mark of the presence of him who has related the incidents.

Benson saw it more emotionally:

The woman then — Seeing other company coming up to interrupt the discourse, immediately left her water-pot — Or pail, behind her, forgetting smaller things, while her thoughts were engrossed with matters of the greatest importance;

Jamieson-Fausset-Brown saw it spiritually:

How exquisitely natural! The presence of strangers made her feel that it was time for her to withdraw, and He who knew what was in her heart, and what she was going to the city to do, let her go without exchanging a word with her in the hearing of others. Their interview was too sacred, and the effect on the woman too overpowering (not to speak of His own deep emotion) to allow of its being continued. But this one artless touch—that she "left her water-pot"—speaks volumes. The living water was already beginning to spring up within her; she found that man doth not live by bread nor by water only, and that there was a water of wondrous virtue that raised people above meat and drink, and the vessels that held them, and all human things. In short, she was transported, forgot everything but One, and her heart running over with the tale she had to tell, she hastens home and pours it out.

The woman finally understood that the living water was more important than the H2O water. Earlier:

13 Jesus said to her, “Everyone who drinks of this water will be thirsty again, 14but whoever drinks of the water that I will give him will never be thirsty again. The water that I will give him will become in him a spring of water welling up to eternal life.”

She had finally got Jesus' point.

From the theatrical perspective, the water jar is a dramatic device.