Genesis 35:18 - Joseph Benson’s Commentary on the Old and New Testaments

As her soul was departing בצאת נפשׁה, when her soul was going out, namely, of the body: an argument this of the soul's immortality, especially if compared with Ecclesiastes 12:7; from which places collated, we learn both whence it goes, and whither it goes. She called his name Benoni The son of my sorrow. Thus, by her own confession, the gaining her desire became her sorrow: a lively instance this of the folly of inordinately desiring any thing temporal: the object obtained generally becomes a source of sorrow to us. But his father called him Benjamin The son of my right hand. As near, dear, and precious to him as his right hand, which is both more useful and more honourable than the left, Psalms 80:17; or, instead of his right hand, the staff, stay, and comfort of his old age. Jacob seems to have given him this name rather than the other, because he would not renew the sorrowful remembrance of his mother's death every time he called his son by name. It may be observed, that both names were remarkably verified in his posterity; the tribe of Benjamin being remarkably brave and active, and yet involved in more sorrowful disasters than were experienced by any of the other tribes.