What joy for those whose strength comes from the Lord,who have set their minds on a pilgrimage to Jerusalem. When they walk through the Valley of Weeping, it will become a place of refreshing springs. The autumn rains will clothe it with blessings. They will continue to grow stronger, and each of them will appear before God in Jerusalem.
and I noticed that after the word "appears" in verse 7 there is a cross reference to Deuteronomy 16:16.
...On each of these occasions, all men must appear before the Lord your God at the place he chooses, but they must not appear before the Lord without a gift for him. 17 All must give as they are able, according to the blessings given to them by the Lord your God.
The progression here is setting your mind on following God, which is a path that inevitably leads to times of sorrow (as does any path in life,) which passes on to refreshing springs and autumn rains that bring blessings. Walking this path, not once, but as a pilgrimage (meaning a long term journey) strengthens us and therefore fits us to appear before the Lord. We are required to give a gift if we are to appear before the Lord, but the gift is not one that originated with us, it is the blessing he gave us during the pilgrimage. Therefore, when we wimp out of the pilgrimage or try to take a route other than the one that goes through the "Valley of Weeping" we miss out on the blessings that come with traveling that path, and therefore miss out on returning those blessings to God.
It is amazing that this is that exact pattern of Christ's life and death, and yet the blessing that he offered in the end was offered to us. These reflections give me good courage, and even joy as described in Psalm 84:5. I think that joy is both the starting point and ending point, though perhaps the process is more cyclical and therefore does not have an ending point. Regardless, I praise God for his mercy, and the goodness he brings from tough times. What a sweet and sustaining glimpse of grace!