C. F. Keil and Franz Delitzsch on Judges 4:19

Jdg 4:19

On his asking for water to drink, as he was thirsty (צמתּי, defective form for צמאתּי), she handed him milk from her bottle, and covered him up again. She gave him milk instead of water, as Deborah emphatically mentions in her song in Jdg 5:25, no doubt merely for the purpose of giving to her guest a friendly and hospitable reception. When Josephus affirms, in his account of this event (Ant. v. 5, 4), that she gave him milk that was already spoiled (διεφθορὸς ἤδη), i.e., had turned sour, and R. Tanchum supposes that such milk intoxicated the weary man, these are merely later decorations of the simple fact, that have no historical worth whatever.