BACA (bā'ka, Heb. bākhā, a balsam tree). KJV, RSV, and NIV in Ps.84.6 all have “the Valley of Baca” (asv “the Valley of Weeping” but with a marginal variant “the valley of the balsam trees”). The tree was called a weeper probably because it exuded tears of gum. There is no trace of a real tree with this name. The phrase refers figuratively to an experience of sorrow turned into joy.

International Standard Bible Encyclopedia (1915)

bakha’: In the King James Version in Ps 84:6, where the Revised Version (British and American) has "the valley of Weeping," with a marginal variant which is best put in the form, "the valley of the balsam-trees." The word is elsewhere used only in the duplicated account of one of David’s battles (2Sa 5:23,24; 1Ch 14:14,15). There the translation is "the mulberry trees," with "the balsam-trees" in the margin in the Revised Version (British and American). Conjecturally the word is, by variant spelling, of the stem which denotes weeping; the tree is called "weeper" from some habit of the trickling of its gum or of the moisture on it; the valley of weeping is not a geographical locality, but a picturesque expression for the experiences of those whose strength is in Yahweh, and who through His grace find their sorrows changed into blessings.

Willis J. Beecher