Related to Hebrew reḥāq 'spiced; spiced wine', and Akkadian ⁠riqqu, rīqu⁠ 'aromatic plants, beer malt'. Wine, at the advent of the Quranic usage, was served warm and brewed from a dehydrated paste or powder form, with spices and practices similar to modern Arabic coffee culture.

    Fraenkel, Siegmund (1886), Die aramäischen Fremdwörter im Arabischen (in German), Leiden: E. J. Brill, page 158 https://archive.org/stream/diearamischenfr00fraegoog#page/n188 
    Freytag, Georg (1830), “رحيق”, in Lexicon arabico-latinum praesertim ex Djeuharii Firuzabadiique et aliorum Arabum operibus adhibitis Golii quoque et aliorum libris confectum‎ (in Latin), volume 1, Halle: C. A. Schwetschke, page 132 https://archive.org/stream/lexiconarabicola01freyuoft#page/n153 
    Jeffery, Arthur (1938), The Foreign Vocabulary of the Qurʾān (Gaekwad’s Oriental Series; 79), Baroda: Oriental Institute, pages 141–142. https://archive.org/stream/in.ernet.dli.2015.217779/2015.217779.The-Foreign#page/n159 
    Müller, David Heinrich (1887), “Arabisch-aramäische Glossen”, in Wiener Zeitschrift für die Kunde des Morgenlandes‎ (in German), volume 1, page 27 https://archive.org/details/wienerzeitschri07oriegoog/page/n36 
    Qian, Ailin (2017), “Delights in Paradise: A Comparative Survey of Heavenly Food and Drink in the Quran”, in Sebastian Günther and Todd Lawson, editors, Roads to Paradise. Eschatology and Concepts of the Hereafter in Islam (Islamic History and Civilization. Studies and Texts; 136/1), Leiden, Boston: Brill, page 256