But Abishai the son of Zeruiah succoured him, and smote the Philistine, and killed him. Then the men of David sware unto him, saying, Thou shalt go no more out with us to battle, that thou quench not the light of Israel. That thou quench not the light of Israel - David is here considered as the lamp by which all Israel was guided, and without whom all the nation must be involved in darkness. The lamp is the emblem of direction and support. Light is used in this sense by Homer: -
Ουδε τι Πατροκλῳ γενομην φαος, αυδ' ἑταροισι
Τοις αλλοις, οἱ δη πολεες δαμεν Ἑκτορι διῳ.
Iliad, lib. xviii. ver. 102.
"I have neither been a Light to Patroclus nor to his companions, who have been slain by the noble Hector."