Albert Barnes Commentary 1 Samuel 11:10

"Therefore the men of Jabesh said, To-morrow we will come out unto you, and ye shall do with us all that seemeth good unto you." — 1 Samuel 11:10 (ASV)

Tomorrow - Probably the last of the seven days’ respite (1 Samuel 11:3). Their words were spoken in guile to throw the Ammonites off their guard.