In 1 Sam. 25:26, there are two English phrases
26 “Now therefore, my lord, as the LORD lives and as your soul lives, since the LORD has held you back from coming to bloodshed and from avenging yourself with your own hand, now then, let your enemies and those who seek harm for my lord be as Nabal. NKJV, ©1982
The Hebrew text translates “the LORD lives” from חַי יְהוָה (chai Yahveh) while “your soul lives” is translated from חֵי נַפְשְׁךָ (chei nafshekha). The difference is the vowel point (nikkud) under the letter ח.
But, why the difference? Why does the Hebrew text have חַי יְהוָה instead of חֵי יְהוָה for “the LORD lives”?