Arha (اَرحاء) (with the zabar of Alif) is an Arabic word that is plural of Raha (رَحَی). It means mill, chest, the part of nail around four sides, jaw (Al-Qamus al-Wahid).
Irha (إرحاء) with the zer of Alif I could not find this word in the dictionary.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband