Albert Barnes Commentary 2 Samuel 2:1

"And it came to pass after this, that David inquired of Jehovah, saying, Shall I go up into any of the cities of Judah? And Jehovah said unto him, Go up. And David said, Whither shall I go up? And he said, Unto Hebron." — 2 Samuel 2:1 (ASV)

Inquired of the Lord - Through Abiathar, the high priest. The death of Saul and Jonathan had entirely changed David’s position, and therefore he needed divine guidance on how to act in the new circumstances in which he was placed. Compare the related passages.

Hebron was well suited for the temporary capital of David’s kingdom, being situated in a strong position in the mountains of Judah, among David’s friends, and also having especially sacred associations. It also appears to have been the center of a district (2 Samuel 2:3).