Some versions add "when he was at Hebron" and others do not. You may want to add the phrase if it is present in your national version. (See: [[rc://en/ta/man/translate/translate-textvariants]])
The original text of this question is not clear. Possible meanings are 1) Abner had the power to give the land to David. AT: "This land is mine!" or 2) David is chosen by God to rule the land: AT: "This land rightfully belongs to you!" (See: [[rc://en/ta/man/translate/figs-rquestion]])
# my hand is with you
Here "hand" represents Abner's assistance that he is offering to David. AT: "I will assist you" (See: [[rc://en/ta/man/translate/figs-metonymy]])