Resh sits at the centre of one of Hebrew's best-documented linguistic mismatches between grammar and mysticism. The Sefer Yetzirah, discussed elsewhere in this atlas, counts Resh as one of its seven double letters, alongside Beth, Gimel, Daleth, Kaph, Peh and Tav, each said to carry both a hard and a soft pronunciation; but the Tiberian Masoretic grammatical rule that actually marks a hard-versus-soft distinction with a dagesh in ordinary vocalised Hebrew, remembered by the acronym begadkefat, covers only six of those seven letters and excludes Resh entirely, since standard Hebrew grammar treats Resh as having a single pronunciation.
The mismatch means Resh is mystically double but grammatically single, a gap Hebrew grammarians and Kabbalists have long noted without fully reconciling. Graphically, Resh is one half of Hebrew's most consequential look-alike pair, needing only a rounded rather than squared trailing corner to be confused with Daleth, discussed elsewhere in this atlas, a distinction Jewish law treats as serious enough to invalidate a scroll if a sofer gets it wrong. A separate homiletic tradition, discussed under Qoph elsewhere in this atlas, also pairs Resh's literal meaning, head, against Qoph's meaning, the back of the head, reading the two letters together as a figure for uprightness set against a turned-away or bowed posture.