Here we go. If you don’t know this one by heart, get to studying. This is our psalm every Friday, but most especially this holiest Friday of the year. No translation I give is going to do this thing justice but here’s my best shot this year.
“Miserere” (Psalm 50)
 In finem. Psalmus David,
Unto the end. A Psalm of David,
 cum venit ad eum Nathan propheta, quando intravit ad Bethsabee.
when there came to him Nathan the prophet, when he had gone into Bathsheba.
 Miserere mei, Deus, secundum magnam misericordiam tuam; et secundum multitudinem miserationum tuarum, dele iniquitatem meam.
Be merciful of me, O God, according to Your great tender-heartedness; and according to the multitude of Your mercies erase my injustice.
 Amplius lava me ab iniquitate mea, et a peccato meo munda me.
Still more wash me from my injustice and from my sin cleanse me.
 Quoniam iniquitatem meam ego cognosco, et peccatum meum contra me est semper.
For my injustice I, even I, know and my sin is against me ever.
 Tibi soli peccavi, et malum coram te feci; ut justificeris in sermonibus tuis, et vincas cum judicaris.
To You alone have I sinned and evil before You have I done; that You may be justified in Your words and conquer when You judge.
 Ecce enim in iniquitatibus conceptus sum, et in peccatis concepit me mater mea.
For behold in injustices have I been conceived and in sins has she conceived me, my mother.
 Ecce enim veritatem dilexisti; incerta et occulta sapientiae tuae manifestasti mihi.
For behold truth have You loved; uncertain and hidden things of Your wisdom have You shown to me.
 Asperges me hyssopo, et mundabor; lavabis me, et super nivem dealbabor.
You will sprinkle me with hyssop and I will be clean; You will wash me and above snow will I be whitened.
 Auditui meo dabis gaudium et laetitiam, et exsultabunt ossa humiliata.
In my hearing You will give joy and happiness and they will exsult, the bones humbled.
 Averte faciem tuam a peccatis meis, et omnes iniquitates meas dele.
Turn away Your face from my sins and all my injustices erase.
 Cor mundum crea in me, Deus, et spiritum rectum innova in visceribus meis.
A clean heart create in me, O God, and a right spirit renew in my bowels.
 Ne projicias me a facie tua, et spiritum sanctum tuum ne auferas a me.
Lest you cast me forth from Your face and Your holy spirit lest You bear it away from me.
 Redde mihi laetitiam salutaris tui, et spiritu principali confirma me.
Give back to me the happiness of Your saving and with a princely spirit strengthen me.
 Docebo iniquos vias tuas, et impii ad te convertentur.
I will teach the unjust Your ways and the impious toward You will be converted.
 Libera me de sanguinibus, Deus, Deus salutis meae, et exsultabit lingua mea justitiam tuam.
Free me from bloods, O God, O God of my health, and it will exalt, my tongue, Your justice.
 Domine, labia mea aperies, et os meum annuntiabit laudem tuam.
O Lord, my lips will You open and my mouth will announce Your praise.
 Quoniam si voluisses sacrificium, dedissem utique; holocaustis non delectaberis.
For if You had desired sacrifice, I would have given surely; in holocausts You will not be delighted.
 Sacrificium Deo spiritus contribulatus; cor contritum et humiliatum, Deus, non despicies.
The sacrifice to God, a spirit all-troubled; a heart crushed and humbled, O God, You will not despise.
 Benigne fac, Domine, in bona voluntate tua Sion, ut aedificentur muri Jerusalem.
Deal benignly, O Lord, in Your good will for Zion, that they may be built, the walls of Jerusalem.
 Tunc acceptabis sacrificium justitiae, oblationes et holocausta; tunc imponent super altare tuum vitulos.
Then You will accept the sacrifice of justice, oblations and holocausts; then they will place above Your altar calves.
v. 3 misericordia vs. miseratio We played this game last year with the prayers of St. Anselm (more specifically, 1B). Two different Latin words, one built from the other, and the book translation for both is “mercy.” Unacceptable! So we need to find a way to keep the Latin clear and not hide the word choice. “Ironically” that prayer translation also had to make a point about benignity (see below). Ironically gets scare-quotes because St. Anselm’s prayer is obviously just riffing off of Psalm 50. Dependency, not irony!
v. 20 has a few interesting bits to it. Benignus means bringing about good things, but here it’s an adverb. Good luck finding a one-word adverb form of that! Do-gooder-ly? The cheating solution is “benignly.” A lot of the non-insane alternatives are made difficult because they duplicate the verb, fac, “to make or do.” The second bit is Sion which, like all OT proper nouns, is indeclinable. It could be anything! Is it a direct object of fac, like “Make Zion” or is it an indirect object, like “Do benignly for Zion”? This is where knowing English translations here gets in the way and colors the decision.