וַיֹּ֧אמֶר אֵלֶ֛יהָ הַשְׁקִינִי־נָ֥א מְעַט־מַ֖יִם כִּ֣י צָמֵ֑אתִי וַתִּפְתַּ֞ח אֶת־נֹ֧אוד הֶחָלָ֛ב וַתַּשְׁקֵ֖הוּ וַתְּכַסֵּֽהוּ׃
Rashi on Judges
The milk pouch. Since milk induces drowsiness, then slumber.10He requested water. Why did she give him milk? To make him drowsy.
Metzudat David on Judges
A pouch of milk: She gave him milk to drink, because it brings on slumber.