Was there a significant age difference between Jonathan and David?

Question:

I read a comment online that some scholars believe that there was a 20 - 30-year difference between Jonathan and David, that Jonathan was at least 20 years older than David.  I have been searching but cannot find scripture that verifies that.  Do you know of one?

Answer:

Jonathan participated in battles against the Philistines when he was first mentioned in I Samuel 13. The typical age for an Israelite warrior to begin was 20 (Numbers 1:2-3). Thus, Jonathan was at least 20 during the second year of Saul's rule (I Samuel 13:1 -- See Saul's War Against the Philistines regarding problems translating this verse).

David fought Goliath when he was just a lad in I Samuel 18. David's older brothers were in the battle against the Philistines. A man had to be at least 20 to be in the army (Numbers 1:3; 26:2). Since David is not with his brothers and it wasn't due to a lack of zeal, we must conclude that David is under the age of 20. David is the eighth son of Jesse. His three eldest brothers were in the army (I Samuel 17:14). David would be at least five years younger than the third son who was in the army. If we assume that the cut-off between the third and fourth son was due to age, that would put David at 15 or less -- this is why he is depicted as a youth and so described: "And Saul said to David, "You are not able to go against this Philistine to fight with him; for you are a youth, and he a man of war from his youth" " (I Samuel 17:33). The Hebrew word for youth is na'ar which refers to someone between infancy and adolescence.

That leaves the question of how many years passed between I Samuel 13 and 17. A reasonable assumption is that Jonathan and David differed by ten to twenty years.

Response:

Excellent! This is precisely what I have been searching for. Thank you.