Either my esteemed relative quoted Archbishop Laud, from the Church of England, and his execution speech, or the pamphleteer decided to add some flourish to his pamphlet.
Here’s Archbishop Laud’s execution speech and his prayer. Archbishop Laud was executed in 1645. It’s possible that the printer wanted to put out a pamphlet about Laud and was using O’Brien as a cover, but most of these kinds of blackletter broadsheets and pamphlets included judicious copying/imitation/plagiarism whenever the printer felt like it.
It just goes to show that sometimes you can’t trust everything that sounds good. Even in 1651.