Old Testament Hebrew does not have a word that expresses the idea of eternity, everlasting or forever in the absolute sense, but as always context is vital in understanding what ‘eternity’ means.
Olam, simply means a indeterminately long duration! Like the following:
1) The duration of a human lifetime (Exodus 14:13; 21:6; Leviticus 25:46; Deuteronomy 15:17).
2) Ten generations (Deuteronomy 23:3).
The Mosaic law schematic was not designed for ‘eternity’. It was for only the 1,500 years leading up to the arrival of Messiah (Galatians 3:19-25).
Conclusion, In relation to context where there is no clear end point described in the text like the a human lifetime or commencement of a new beginning we should assume that olam means ‘everlasting’.