C. F. Keil and Franz Delitzsch on Proverbs 20:21

Pro 20:21 21 An inheritance which in the beginning is obtained in haste,      Its end will not be blessed.

The partic. מבחל may, after Zec 11:8, cf. Syr. bhlaa', nauseans, mean “detested,” but that affords here no sense; rather it might be interpreted after the Arab. bajila, to be avaricious, “gotten by avarice, niggardliness,” with which, however, neither נחלה, inheritance, nor, since avarice is a chronic disease, בּראשׁונה agrees. On the contrary, the Kerı̂ מבהלת [hastened] perfectly agrees, both linguistically (vid., Pro 28:22; cf. Pro 13:11) and actually; for, as Hitzig remarks, the words following Pro 20:20 fully harmonize with the idea of an inheritance, into the possession of which one is put before it is rightly due to him; for a son such as that, the parents may live too long, and so he violently deprives them of the possession (cf. Pro 19:26); but on such a possession there rests no blessing. Since the Piel may mean to hasten, Est 2:9, so מבהל may mean hastened = speedy, Est 8:14, as well as made in haste. All the old interpreters adopt the Kerı̂; the Aram. render it well by מסרהבא, from מסרהב, overturned; and Luther, like Jerome, haereditas ad quam festinatur.