It is unclear what the question is actually asking.
1) The Book of Esther, upon which Purim is based, came at the end of the Old Testament, so if this is referring exclusively to the time period of the Old Testament, Purim would not have meant anything because it did not exist.
(It would be like asking what did the Treaty of Paris of 1783 mean to the American Colonists during their early history.)
2) Jews today still use exclusively the Old Testament and Jews claim that their religion has not changed since those days. To Jews today, Purim signifies how God intervenes and protects the Jewish people even without performing a Deus Ex Machina like he did in Egypt.
The old testament was addressed to the Jews.
In the old testament the Jews were not allowed to mingle with the gentiles especially the samaratins.
The old testament is made of the history of the Jews and the prophecies of the prophets , and life of the Jews under king.
YES. Compared with any other religion, Jews have the strongest focus on the Old Testament.
The Old Testament is primarily followed by Christians and Jews. Christians use both the Old and New Testaments as part of their religious scripture, while Jews primarily follow the Old Testament, which they refer to as the Tanakh.
The old testament is important to the Jews, but also to all christians.
JEWS
Christians and Jews today believe and study the Old Testament. The Jews made it, but as Jesus was Jewish, Christians study it too.
Muslims and Jews both believe in One God, reject the concept of the trinity, and honor the Prophets of the Old Testament. Muslims and Jews both believe in One God, reject the concept of the trinity, and honor the Prophets of the Old Testament.
Orthodox Jews read all the 24 books of the Bible (Old Testament).
All Jews and most Christians honor the Old Testament as canonical.
Canaanites. The Jews