This phrase appeared on a preliminary sketch of Thrór’s Map from 1936. The final form of the map appeared in the first edition of The Hobbit without the phrase. Rhona Beare copied the phrase from a display of the sketch in the British Museum, and the phrase was first published in 1989 in Parma Eldalamberon #6 and Vinyar Tengwar #7 (PE06/38, VT07/7). The sketch itself appears in J.R.R. Tolkien: Artist and Illustrator (TAI/92, illustration #85), and a rendition of the phrase appears in a footnote (TAI/150, note #6).
Hammond and Scull interpreted the phrase in the footnote mentioned above. An analysis of the phrase also appears in an article by Didier Willis titled “Une phrase elfique dans « J. R. R. Tolkien, Artist & Illustrator »” (PED-TAI) and also in David Salo’s A Gateway to Sindarin (GS/216-7). These three analyses are very close and form the basis for the version presented here.
Tolkien gave two translations of the phrase in the sketch. There is a Modern English translation “five foot high the door and three may walk abreast”, written in runes. There is also an Old English translation: “fif fota heah is se dura and þrie maeg samod þurghgangend”, in Modern English: “five foot high is the door and three may together through-go”.
The first part of the phrase is clear. The first word is lheben “five”, followed by the plural form teil “feet” of tâl “foot”. The third word is brann, which is translated in The Etymologies as “lofty, noble, fine” (Ety/BARÁD) but here seems to mean “high”. The fourth word is the definite article i “the” and the fifth is annon “gate, door”. The sixth word ar is a variant of a “and” (like its cognate ᴹQ. ar) followed by neledh “three”.
The remainder of the phrase is difficult to interpret. The eighth word is illegible. Rhona Beare thought it might be ?nelwhi or ?maohi (VT07/7). Hammond and Scull rendered it as neledhi, which they interpreted as a variant of neledh “three”, so that neledh neledhi means “three by three”. Willis and Salo suggested instead that neledhi means “to walk [in]” (PED-TAI, GS/217), the infinitive of an unattested verb ✱neledh- “to go in, enter” (GS/276). Willis further suggested that it was written over a rejected form neledie (also noted, but not interpreted, by Hammond and Scull), the Old Noldorin form of the word. Willis and Salo analyzed this verb as a combination of the prefix ✱ne- “in” (also seen in N. nestag- “stick in”) and a derivative of the root ᴹ√LED “go, fare, travel”. If the eighth word corresponds to English “walk [in]”, then this interpretation is quite plausible.
The ninth word gar seems to be a verb corresponding to English “may” in the sense “can, be able to”. Salo suggested that it is the Noldorin verb gar-, but this is translated “hold, have” in The Etymologies (Ety/GAR), which does not seem appropriate. Willis suggested that it is the (Early Noldorin?) verb ᴱN. gar “went” seen in the phrase ven Sirion gar meilien “towards (the river) Sirion went laughing”; Hammond and Scull also suggested it might be a verb meaning “go”. A third possibility is that it is a soft mutation of the verb car- “do, make” (Ety/KAR), perhaps lenited because it follows an infinitive form; the meaning of car- seems to me to be a bit closer in sense to “may”, but this is still just a guess.
The last word godrebh might correspond to English “abreast”, but Hammond, Scull, Willis and Salo all suggested that it means “together through”, matching the Old English “samod þurgh”. Willis and Salo both independently analyzed this word as the prefix go- “together” and a lenited prefixal form dre of trî “through”, with the final -bh (pronounced [v]) marking it as an adverb (PED-TAI, GS/217). The word godrebh was preceded by some deleted and unclear writing, rendered ?goldegoelend by Rhona Beare (VT07/7), perhaps two rejected forms ?golde >> goelend (?“together-go”), though Hammond and Scull transcribed the two rejected forms as golda >> goelend (TAI/150, note #6).