This gives us some idea of the importance of the concept of prayer. There is another fundamental principle here - that of deficiency. Esther hoped to cause Haman to fall asleep, to blunt his alertness. Therefore she sought to satisfy him. He engages not only in prayer of praise and thanksgiving, but also in petition.
Prayer can be an experience which nourishes a person for many subsequent years.
We spoke of the necessity of petition to God. Suddenly one of the teachers stood up and began sharing with all those present a prayer experience which he had had some dozen years previously. After a short time his voice began to shake. A person can live his prayer and relive it for years thereafter. Every prayer has the potential to serve as such an experience.