And Saul (d) eyed David from that day and forward.
(d) Because he envied and hated him.

And Saul eyed David from that day and forward. Instead of looking pleasantly, and with a smile, upon him, as a courtier and favourite, he was justly entitled to by his gallant behaviour, he looked at him with a sour, ill natured look; he looked at him with an evil, spiteful, malicious, and envious eye; or he diligently watched and observed all his motions and actions, whether they tended to disloyalty and treason, to dethrone him, and take the kingdom to himself, which he was suspicious of; he laid wait for him, as the Targum, and laid snares too, as the following history shows.

Saul eyed David--that is, invidiously, with secret and malignant hatred.

From that day forward Saul was looking askance at David. עון, a denom. verb, from עין, an eye, looking askance, is used for עוין (Keri).