Jeremiah 4:14 - Matthew Poole's English Annotations on the Holy Bible

O Jerusalem, wash thine heart; cleanse your inward parts, O ye men of Jerusalem; not your hands only, as hypocrites do, but your hearts, James 4:8. The same exhortation with Jeremiah 4:3,4, only in another metaphor of washing, which seems to be taken from such potions first physicians give to clear away the inward parts from noxious humours. See Isaiah 1:16,17. From wickedness; viz. from all filthiness of flesh and spirit, 2 Corinthians 7:1 James 1:21. That thou mayest be saved: this hath reference in this place to temporal salvation; it is prescribed as a means to prevent the judgments that are impending on them, as is plainly expressed, Jeremiah 4:4, yet not exclusive of spiritual salvation, 2 Thessalonians 2:13 Titus 3:5. Vain thoughts; wicked thoughts, or rather hopes or expectation from any helps, Jeremiah 2:5,37; pleasing thyself with vain fancies of safety and security, which thoughts of thine will assuredly bring ruin and misery upon thee, which is inevitably coming, as in the next verse.