Jamieson, Fausset and Brown on 1 Samuel 9:7

7. Saul said to his servant, But, behold, if we go, what shall we bring the man?--According to Eastern notions, it would be considered a want of respect for any person to go into the presence of a superior man of rank or of official station without a present of some kind in his hand, however trifling in value.

the bread is spent in our vessels--Shepherds, going in quest of their cattle, put up in a bag as much flour for making bread as will last sometimes for thirty days. It appears that Saul thought of giving the man of God a cake from his travelling bag, and this would have been sufficient to render the indispensable act of civility--the customary tribute to official dignity.