'Once' in the Bible

Gideon said to God, "Don't let your anger be kindled against me, and I will speak but this once. Please let me make a trial just this once with the fleece. Let it now be dry only on the fleece, and on all the ground let there be dew."

When Delilah saw that he had told her all his heart, she sent and called for the lords of the Philistines, saying, "Come up this once, for he has told me all his heart." Then the lords of the Philistines came up to her, and brought the money in their hand.

Samson called to Yahweh, and said, "Lord Yahweh, remember me, please, and strengthen me, please, only this once, God, that I may be at once avenged of the Philistines for my two eyes."