This text comes from The Army and Navy Hymnal, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
HAVE mercy upon me, God, according to thy lovingkindness:
According to the multitude of thy tender mercies blot out my transgressions.
Wash me thoroughly from mine iniquity, and cleanse me from my sin.
For I know my transgressions; and my sin is ever before me.
Against thee, thee only, have I sinned, and done that which is evil in thy sight;
That thou mayest be justified when thou speakest, and be clear when thou judgest.
Behold, I was brought forth in iniquity; and in sin did my mother conceive me.
Behold, thou desirest truth in the inward parts;
And in the hidden part thou wilt make me to know wisdom.
Purify me with hyssop, and I shall be clean:
Wash me, and I shall be whiter than snow.
Make me to hear joy and gladness, that the bones which thou hast broken may rejoice.
Hide thy face from my sins, and blot out all mine iniquities.
Create in me a clean heart, O God; and renew a right spirit within me.
Cast me not away from thy presence; and take not thy holy Spirit from me.
Restore unto me the joy of thy salvation; and uphold me with a willing spirit.
Then will I teach transgressors thy ways;
And sinners shall be converted unto thee.
Deliver me from bloodguiltiness, O God, thou God of my salvation;
And my tongue shall sing aloud of thy righteousness.
O Lord, open thou my lips;
And my mouth shall show forth thy praise.
For thou delightest not in sacrifice; else would I give it;
Thou hast no pleasure in burnt-offering.
The sacrifices of God are a broken spirit:
A broken and a contrite heart, O God, thou wilt not despise.