The psalmist encouraged the Israelite pilgrims to pray for continuing deliverance. The mention of Zion, the pilgrim's destination, recalled the place where God dwelt, the most important place in Israel. Those who hated Zion would be hating and setting themselves against Yahweh. Grass and weed seeds often blew onto the flat roofs of the Israelites' houses, but they did not flourish long because they had little soil in which to root. In Israel it was customary to greet someone by wishing God's blessing on them (cf. Ruth 2:4). However the psalmist prayed that Israel's enemies would receive no such greeting.
God's people should carefully thank Him for past deliverances but should also continue to pray for His safe keeping in the future since their enemies will continue to oppose and oppress them.
