Proverbs 8:4-5 Unto you, O men, I call; and my voice is to the sons of man. O you simple, understand wisdom: and, you fools, be you of an understanding heart. 

‘Sons of man’ – The call is to all the sons of Adam – to the simple, to the fools (8:4-5).

‘Simple’ [Hebrew: pethiy] inconsiderate; unwary; artless, guileless, and unsuspecting; those who, through lack of knowledge and experience, act rashly and unwisely (1:22, 32; 7:7; 8:5; 9:4, 16; 14:15, 18; 19:25; 21:11; 22:3; 27:12). Referring to those who are unsaved.

‘Wisdom’ [Hebrew: ‛ormah] shrewdness. Translated as wisdom (8:5); subtilty (1:4); and prudence (8:12).

‘Heart’ – Eighteen commands concerning the heart: Apply the heart to understanding (2:2; 22:17; 23:12). Open the heart to wisdom (2:10). Keep the commandments (3:1; 4:4, 21). Write commandments on it (3:3; 7:3). Trust in the Lord with it (3:5). Keep it with all diligence (4:23). Bind commandments upon it (6:21). Do not lust in it (6:25). Do not be inclined to sin (7:25). Have an understanding heart (8:5). Be wise in it (11:29; 12:23; 16:21). Retain wisdom in it (14:33). Be merry in heart (15:13, 15). Study answers with it (15:28). Increase its knowledge (18:15). Apply it to instruction (23:12). Do not use it to envy sinners (23:17). Give heart to wisdom (23:26).