And Saul cast a javelin at him to smite him
So provoked to wrath was he by what he said. It seems by this that Saul always had a javelin or spear in his hand, which is to be accounted for by the custom of those times; in other countries, as well as in this, the kings used to carry spears in their hands instead of sceptres, and which they used as such; so Justin F8, speaking of the times of Romulus, says, that kings in those times had spears, as an ensign of royalty, which the Greeks call sceptres; and so the Greeks called sceptres spears F9:
whereby Jonathan knew that it was determined of his father
for since he attempted to smite him, his own son, for speaking on his behalf, it might be well concluded, that such was his settled wrath and malice, that he would if possible kill David, could he get him into his hands.