In verse 18 the Hebrew reads “If I had seen iniquity in my heart,” by which the psalmist means that if he had been aware of his sin yet done nothing about it; so Revised Standard Version If I had cherished iniquity; Good News Translation “If I had ignored my sins.” But Traduction œcuménique de la Bible translates “If I had thought about (doing) evil”; New Jerusalem Bible “Had I an evil thought in my mind”; and Bible en français courant “If I had had wicked intentions.” This, however, had not happened; the psalmist had confessed his sins or else had not been guilty of any sins; and so his prayer was answered. Good News Translation “ignored my sins” is rendered in idiomatic forms in some languages; for example, “If I turned my head from my sins,” “If I had shut my eyes on the evil I had done,” and “If I had put deaf ears on my sins.”

Verse 18b states what would have happened if the psalmist had not been aware of and confessed his sins; God would not have listened to his prayer, that is, God would not have done what he had asked God to do.

Verse 19 shows that the psalmist has repented of his sins and confessed them to God, inasmuch as God has listened to his prayer and answered his pleas. Voice of my prayer means “sound of my prayer,” but Good News Translation “my prayer” is an adequate rendering. Or else, “when I spoke my prayer.”

Quoted with permission from Bratcher, Robert G. and Reyburn, William D. A Handbook on the Book of Psalms. (UBS Helps for Translators). New York: UBS, 1991. For this and other handbooks for translators see here .