'Once' in the Bible

So the Lord allowed those nations to remain, not driving them out at once; and He did not give them into the hand of Joshua.

Then Gideon said to God, “Do not let your anger burn against me, so that I may speak once more. Please let me make a test once more with the fleece; now let only the fleece be dry, and let there be dew on all the ground.”

Then Delilah realized that he had told her everything in his heart, so she sent and called for the Philistine lords, saying, “Come up this once, because he has told me everything in his heart.” Then the Philistine lords came up to her and brought the money [they had promised] in their hands.

Then Samson called to the Lord and said, “O Lord God, please remember me and please strengthen me just this one time, O God, and let me take vengeance on the Philistines for my two eyes.”