C. F. Keil and Franz Delitzsch on Psalms 37:37-38

Psa 37:37-38 תּם might even be taken as neuter for תּם, and ישׂר for ישׁר; but in this case the poet would have written רעה instead of ראה; שׁמר is therefore used as, e.g., in 1Sa 1:12. By כּי that to which attention is specially called is introduced. The man of peace has a totally different lot from the evil-doer who delights in contention and persecution. As the fruit of his love of peace he has אחרית, a future, Pro 23:18; Pro 24:14, viz., in his posterity, Pro 24:20; whereas the apostates are altogether blotted out; not merely they themselves, but even the posterity of the ungodly is cut off, Amo 4:2; Amo 9:1; Eze 23:25. To them remains no posterity to carry forward their name, their אחרית is devoted to destruction (cf. Psa 109:13 with Num 24:20).