I Samuel 18:9 Commentary: Rashi

וַיְהִ֥י שָׁא֖וּל עון [עוֹיֵ֣ן] אֶת־דָּוִ֑ד מֵהַיּ֥וֹם הַה֖וּא וָהָֽלְאָה׃ (ס)

And Saul eyed David from that day and forward.