Updated: Feb 19, 2018
Verse 18: And Jael went out to meet Sisera, and said unto him, Turn in, my lord, turn in to me; fear not. And when he had turned in unto her into the tent, she covered him with a mantle (or, rug, or, blanket).
[Enter unto me, סוּרָ֥ה אֵלַ֖י] Divert (withdraw [Tigurinus], turn aside [Pagnine]) to me (Munster, Junius and Tremellius).
Fear not: this was a promise of security, and therefore she cannot be excused from dissimulation and treachery in the manner, though the substance of her act was lawful and worthy.
[He was covered by her with a cloak, בַּשְּׂמִיכָה] With a covering (Pagnine, Montanus), that is, a thick one (Montanus); with a mattress (Munster), blanket (Castalio), cloak (Arabic), curtain of the tent (Syriac), shaggy rug (Vatablus), amphitapa, carpet with pile on both sides (Junius and Tremellius). Ἀμφίταπος/ amphitapos to Athenæus is a type of garment having shaggy hair on both sides (Drusius). With a rug. It has its etymological root from density. For סוּמְכָּה in the Chaldean and סמכה in the Arabic both mean thickness, density. And Kimchi says upon the Chaldean of this passage that גּוּנְכָּא/gunca is a thicker sort of rug, shaggy on both sides (Bochart’s Sacred Geography “Phaleg” 1:42:748). She did this cunningly; so that she might allay suspicion of deceit, she hid him, lest one of the Hebrews should find him (Bonfrerius).
Verse 19: And he said unto her, Give me, I pray thee, a little water to drink; for I am thirsty. And she opened (Judg. 5:25) a bottle of milk, and gave him drink, and covered him.
[Give…a little water] He does not say, wine; 1. because it was known that this was not to be found among the Kenites; see Jeremiah 35; 2. because water is more agreeable to the thirsty (Bonfrerius, Menochius).
[I am very thirsty] Of course, he is exhausted from running, the swift flight, labor, and fear (Menochius).
[A skin of milk] Either, because water was not at hand (Drusius); or, so that the drink might be more pleasant (Vatablus); as evidence of greater benevolence (Menochius, Bonfrerius, Lapide); or, so that she might induce him to sleep (Vatablus, Lapide, Bonfrerius, Martyr, Montanus’ Commentary). For milk, if it be consumed in large quantities, is wont raise vapors and fumes, which, ascending to the head, render one disposed to cold/heaviness and sleep. Hence infants sleep often; and milk is wont to be denied to the bilious and those sick with fever by Physicians, as Hippocrates testifies (Lapide out of Tostatus). Perhaps with the milk she mixed opium, mandragora, etc. (Lapide).
Gave him milk to drink; either because she had not water in her tent, and pretended fear of discovery or some inconvenience if she went out to fetch it; or as a signification of greater respect; or as a likely mean to cast him into a sleep, which she desired and designed; to which end possibly she might mix something with it to cause sleep, which she could not so conveniently have done with water. Covered him, upon pretence of hiding him, but really to dispose him to sleep.
Verse 20: Again he said unto her, Stand in the door of the tent, and it shall be, when any man doth come and enquire of thee, and say, Is there any man here? that thou shalt say, No.
[And Sisera said to her, Stand (thus Munster, Tigurinus, Junius and Tremellius, Drusius), עֲמֹד] Or, he said to stand, that is, that she should stand (Drusius). He speaks imperiously enough, and addresses her as if a maidservant, whom he ought to have acknowledged as mistress of her family (Montanus’ Commentary).
[There is no one] But she cunningly leaves the promissory response to his stipulation unspoken (Junius).
He said unto her, etc.: He speaks imperiously to her; but it is observable, that she gives him no promise to do so, nor makes him any answer; possibly because though she knew her design upon him was warrantable, yet she had proceeded too far in using dissimulation therein.
 Hebrew: וַתֵּצֵ֣א יָעֵל֮ לִקְרַ֣את סִֽיסְרָא֒ וַתֹּ֣אמֶר אֵלָ֗יו סוּרָ֧ה אֲדֹנִ֛י סוּרָ֥ה אֵלַ֖י אַל־תִּירָ֑א וַיָּ֤סַר אֵלֶ֙יהָ֙ הָאֹ֔הֱלָה וַתְּכַסֵּ֖הוּ בַּשְּׂמִיכָֽה׃
 Hebrew: בַּשְּׂמִיכָה.
 Athenæus of Naucratis (late second-early third century AD) wrote Deipnosophistæ (or Banquet of the Learned), a dialogue in which the characters discuss a wide range of topics. The Deipnosophistæ preserves much information about the ancient world that would have otherwise been lost.
 Hebrew: וַיֹּ֧אמֶר אֵלֶ֛יהָ הַשְׁקִינִי־נָ֥א מְעַט־מַ֖יִם כִּ֣י צָמֵ֑אתִי וַתִּפְתַּ֞ח אֶת־נֹ֧אוד הֶחָלָ֛ב וַתַּשְׁקֵ֖הוּ וַתְּכַסֵּֽהוּ׃
 Aphorisms 64:5. Hippocrates (circa 460-370 BC) was a Greek physician, known as “The Father of Medicine”.
 Hebrew: וַיֹּ֣אמֶר אֵלֶ֔יהָ עֲמֹ֖ד פֶּ֣תַח הָאֹ֑הֶל וְהָיָה֩ אִם־אִ֙ישׁ יָב֜וֹא וּשְׁאֵלֵ֗ךְ וְאָמַ֛ר הֲיֵֽשׁ־פֹּ֥ה אִ֖ישׁ וְאָמַ֥רְתְּ אָֽיִן׃
 Formally עֲמֹד can be either imperative or infinitive.