On a practical level, the lampstand illuminated the holy place and provided access to God for those who made intercession or performed other spiritual services. The light was also symbolic. In the Bible, particularly the Psalms, light represents the Lord (Psalm 27:1; Psalm 36:9).
4 Il arrangera les lampes sur le chandelier d'or pur, pour qu'elles brûlent continuellement devant l'Eternel.