ما المقصود بالعُمَرَين؟

The intended meaning of "the two 'Umars" is Abu Bakr As-Siddiq and 'Umar ibn Al-Khattab, may Allah be pleased with them both. This designation was used by way of giving precedence to one of the names over the other, which is a well-known Arabic linguistic style, similar to referring to the sun and moon as "the two moons" (al-qamarayn), or to the father and mother as "the two parents" (al-abawayn).