The wisest of all men – King Solomon, teaches in his work Mishlei (Proverbs 13:12), “Hope deferred (a drawn out hope) makes the heart sick, but a desire that is realised is a tree of life!” Rashi explains this to refer to to someone who trusts in his friend to help him – but he does not; but when a desire is realised, it is like a tree of life – this refers to God who awaits for the Jewish people to return to Him (through the observance of mitzvot, the study of Torah, acts of goodness and kindness to others etc.) but they don’t return; in the end it brings them to a sickness of the heart; but when His desire is fulfilled, then it is like a tree of life to them!