Hebdomekonta is the Greek numeral seventy. It appears in the sending of the seventy (or seventy-two) disciples (Luke 10:1), in Peter's question about forgiving 'seventy times seven' (Matthew 18:22), and in references to the Seventy elders of Israel (used in Exodus) and the Septuagint (LXX = seventy).
Seventy in Scripture symbolizes the fullness of nations (Genesis 10 lists 70 nations) and organizational completeness among God's people. The seventy elders of Israel (Exodus 24:1), the seventy-year Babylonian exile (Jeremiah 29:10), Daniel's seventy weeks (Daniel 9:24), and Jesus sending out seventy disciples all connect to this number. Most profoundly, when Peter asked if forgiving 'up to seven times' was sufficient, Jesus replied 'seventy times seven' — not a cap of 490 acts of forgiveness but a call to limitless, uncountable forgiveness mirroring divine grace.