Occasionally, a Hebrew word will change its vowel pointing due to the fact that it is “in pause”.  video  These so-called “pausal forms” are any Hebrew word that occurs with any of the following accents; an atnah, a silluq, or a zaqef-katon. Notice the last word in this verse (Gen. 20:9):

וַיִּקְרָ֨א אֲבִימֶ֜לֶךְ לְאַבְרָהָ֗ם וַיֹּ֨אמֶר ל֜וֹ מֶֽה־עָשִׂ֤יתָ לָּ֙נוּ֙ וּמֶֽה־חָטָ֣אתִי לָ֔ךְ

Notice the mark that looks like a colon above the lamed. That is a zaqef-katon. Because of the presence of this accent mark, this word is said to be in pause. This also accounts for the fact that the pronominal suffix here looks feminine when we know it is really masculine (the antecedent is Abraham).