pa.tsah describes opening, especially of a mouth or the ground, and can introduce speech spoken to the LORD.

The attested use most often concerns a mouth being opened, whether for hostile speech, empty speech, or speech addressed to the LORD; it also describes the ground opening its mouth to receive or swallow. In the vow scene, opening the mouth to the LORD introduces words that cannot be taken back.

1. Opening a mouth for speech or expression · dominant

   In Isaiah 10:14, the active participle occurs in the clause where no one opens a mouth or chirps. In Job 35:16 the imperfect stands in the statement that Job opens his mouth in vanity, while Lamentations 2:16 and Lamentations 3:46 describe enemies opening their mouths or lips against the speaker.

   Isaiah 10:14Job 35:16Lamentations 2:16Lamentations 3:46
2. The ground opening its mouth · common

   Genesis 4:11 describes the ground as having opened its mouth to receive blood. Deuteronomy 11:6 and Numbers 16:30 likewise place the feminine singular form with the land or ground opening its mouth and swallowing people and their possessions.

   Genesis 4:11Deuteronomy 11:6Numbers 16:30
3. Opening the mouth in a binding utterance · occasional

   In Judges 11:35, the first-person perfect occurs in the speaker's statement that he has opened his mouth to the LORD and cannot take back his vow. Judges 11:36 repeats the expression in the daughter's reply and connects what has gone out of his mouth with the requested action.

   Judges 11:35Judges 11:36

In the Anselm Project Bible: Where the clause is clear, the APB commonly renders the action with “opened,” as for the ground in Genesis 4:11 and a mouth in Job 35:16. In Judges 11:35 and Judges 11:36 it presents the expression as opening the mouth to the LORD.