The number 55 is best known from Manasseh's reign in Jerusalem, the longest of any Jewish king, but has no well-established independent symbolic meaning in biblical tradition.
The number 55 appears in the Bible primarily as the length of King Manasseh's reign in Jerusalem (2 Kings 21:1; 2 Chronicles 33:1). Manasseh is counted as the king who reigned longest in Judah, but his rule is described in very negative terms: he reintroduced idolatry, built altars for foreign gods in the temple and "poured out so much innocent blood that he filled Jerusalem from one end to the other" (2 Kings 21:16). Paradoxically, Chronicles also tells us that Manasseh eventually repented while in captivity and sought the Lord (2 Chronicles 33:12–13), which makes him a complex figure – an image of both long-lasting sin and the possibility of repentance. Beyond this historical reference, the number 55 has no prominent symbolic role in the Bible or in classical Jewish numerology, where numbers such as 7, 12 and 40 have far stronger and more established meanings. 55 is the tenth triangular number, that is, the sum of the numbers 1 to 10. Some have tried to link this to completeness through the Ten Commandments, but this is not a widely recognized traditional interpretation. In rabbinic tradition, Manasseh's repentance is an important theme. The Talmud (Sanhedrin 103a) discusses whether Manasseh has a share in the world to come, and his remorse is used as an example that even the most sinful can return to God (teshuva). Manasseh's 55-year reign (c. 697–642 BC) fell during a period when Judah was a vassal state under the Neo-Assyrian Empire, which may have contributed to the religious syncretism for which he is criticized.*