Jamieson, Fausset and Brown on James 1:19

19. Wherefore--as your evil is of yourselves, but your good from God. However, the oldest manuscripts and versions read thus: "Ye know it (so Ep 5:5; He 12:17), my beloved brethren; BUT (consequently) let every man be swift to hear," that is, docile in receiving "the word of truth" (Jas 1:18, 21). The true method of hearing is treated in Jas 1:21-27, and Jas 2:1-26.

slow to speak--(Pr 10:19; 17:27, 28; Ec 5:2). A good way of escaping one kind of temptation arising from ourselves (Jas 1:13). Slow to speak authoritatively as a master or teacher of others (compare Jas 3:1): a common Jewish fault: slow also to speak such hasty things of God, as in Jas 1:13. Two ears are given to us, the rabbis observe, but only one tongue: the ears are open and exposed, whereas the tongue is walled in behind the teeth.

slow to wrath--(Jas 3:13, 14; 4:5). Slow in becoming heated by debate: another Jewish fault (Ro 2:8), to which much speaking tends. Tittmann thinks not so much "wrath" is meant, as an indignant feeling of fretfulness under the calamities to which the whole of human life is exposed; this accords with the "divers temptations" in Jas 1:2. Hastiness of temper hinders hearing God's word; so Naaman, 2Ki 5:11; Lu 4:28.