וַהֲוָה בְּפַלְגוּת לֵילְיָא וּתְוַהּ גּוּבְרָא וּרְתֵית וְאִתְרַכִּיךְ כְּלִפְתָּא בִּשְׂרֵיהּ מִן רְתֵיתָא וַחֲזָא אִתְּתָא דָּמְכָא לָקֳבֵל רַגְלוֹי וּכְבַשׁ יִצְרֵיהּ וְלָא קְרֵיב לְוָתַהּ הֵיכְּמָא דַּעֲבַד יוֹסֵף צַדִּיקָא דְּסָרֵיב לְמִקְרַב לְוָת מִצְרֵיתָא אִתַּת רִבּוֹנֵיהּ וְהֵיכְּמָא דַּעֲבַד פַּלְטִיאֵל בַּר לַיִשׁ חַסִּידָא דִּנְעַץ סַיְפָא בֵּין מֵימְרֵיהּ וּבֵין מִיכַל בַּת שָׁאוּל אִתַּת דָּוִד דְּסָרֵיב לְמִקְרַב לְוָתַהּ.
1. trembled | וַיֶּחֱרַד – This might mean that Boaz was startled awake, or perhaps that he shuddered in some dream or from the cold, leading him to move and notice Rut. Alternatively, he trembled only after he realized that someone else was lying beside him and then twisted to see who it was (Pseudo-Rashi). Cf. R"Y Kara (and Akeidat Yitzchak similarly), that the order of the verse should be inverted. After stretching and twisting (in sleep or upon awakening), he felt Rut, and then trembled in fright.
2. twisted around | וַיִּלָּפֵת – The verb might refer to twisting and turning in sleep (Akeidat Yitchak), to stretching upon waking (R"Y Kara), or to Boaz's turning around after noticing that someone was by his side (Pseudo-Rashi, Ralbag). Alternatively: "grasp" (Rashi and Rid). Besides here, the root "לפת" appears only in Shofetim 16:29 and Iyyov 6:18. From context, in the former it appears to mean "grasp", while in the latter it seems to mean: "to wind around". See BDB that the Arabic cognate "لَفَت" supports the translation of "twist".