Psalms 118:19 - Matthew Poole's English Annotations on the Holy Bible

Open to me, O ye porters, appointed by God for this work. Or it is a figurative and poetical manner of expression, whereby he speaks to the gates themselves, as if they had sense and understanding. Or by saying open, he implies that they had been long shut against him in Saul's time. The gates of righteousness, to wit, the gates of the Lord's tabernacle, the proper and usual place of the solemn performance of the duty here following, which he calleth the gates of righteousness, partly, in opposition to the gates of death, of which he speaks implicitly Psalms 118:18, and expressly Psalms 9:13, Psalms 107:18, which may be called the gates of sin or unrighteousness, because death is the wages of sin; partly, because there the rule of righteousness was kept and taught, and the sacrifices of righteousness (as they are called, Psalms 4:5) were offered, and divers other exercises of righteousness or of God's service were performed; and partly, because those gates were to be opened to all righteous persons, (such as David had oft professed and proved himself to be, upon which account he claims this as his just privilege,) and only to such, for the unclean and unrighteous were to be shut and kept out by the porters, 2 Chronicles 23:19: compare Isaiah 26:2.