ر ح بr-ḥ-b
(ک) رَحُبَ يَرْحُبُ رُحْبًاraḥuba yarḥubu ruḥban: for a place to be spacious. ﴿وَضَاقَتْ عَلَيْكُمُ الْاَرْضُ بِمَا رَحُبَتْ﴾ (At-Tawbah 9:25)
مَرْحَبٌmarḥab (noun of time or place, ẓarf, on the pattern of مَفْعَلmafʿal): a time or occasion of spaciousness; mostly used in the sense of welcome. ﴿لَا مَرْحَبًۢا بِهِمْ﴾ (Ṣād 38:59)