The teenage victim was taken to an area hospital with serious injuries after the stabbing in Whitman on Sunday night, police said.
The victim, who is a sophomore at Whitman-Hanson Regional High School, was taken to South Shore Hospital in Weymouth following the stabbing, which occurred around 9 p.m.
Police said in a news conference Monday the two teens "definitely knew each other."
Jared Wark, a classmate of both teens, said the stabbing stemmed from an argument that started over social media.
"I guess the kid wasn’t invited to a sleepover and then the victim, he was like, no more talking let's just fight," Wark said."And I guess the kid who stabbed him was like, if you come to my house and I’ll stab you and no one thought he was serious because he’s not that kid, no one thought and he came to his house came out and stabbed him and ran back into the house."
Investigators combed the area,and sources said a 4-inch knife was found at the scene.
As of Monday morning, the victim was expected to survive his injuries after spending hours in surgery. Police say he has a long recovery ahead of him.