Psalm 121 is a psalm of ascents. This group of psalms were traditionally sung by pilgrims in the regular ‘ascent’ to Jerusalem for the sacred feasts. It celebrates the covenant relationship with God. The hills being spoken of here are specifically those of mount Zion (Jerusalem). Jerusalem, with the temple in its midst, was the place where God dwelt in a formal and favourable sense. It was the place where people went to meet with God together. As the pilgrims looked ahead up the road they travelled they could see the great mount of Jerusalem and were inspired by the anticipation of the blessings they would receive there in God’s presence. But God’s presence, as I said in the commentary on Psalm 24, is not bound to a place. God used the physical presence of the temple to remind his people that he was dwelling in their midst. In fact God is everywhere and in a special sense he is with his people watching over them. God sees everyone at every time but this watching spoken of here is more than just seeing ‘ it is the watching of a zealously protective parent. God will not allow his children to be eternally harmed by the threats of life. The idea of pilgrimage is a wonderful metaphor of the Christian life. Those who came to Jerusalem were faced with many threats along the way. Thieves made the most of the gift laden pilgrims whenever they could. But the psalm says that God will watch over the coming and going of his people as the head for the holy city. This life is not meant to be one of aimless wandering. Those who are in covenant with God live their lives as a pilgrimage to the holy city, the heavenly Jerusalem. There are many threats along the way and Satan always prowls around like a roaring lion, as Peter says. But God will keep his people secure in his love and will bring them home safely whatever the obstacles.