Institutes which are entirely ordered to contemplation always hold a distinguished place in the mystical Body of Christ: for they offer an extraordinary sacrifice of praise to God, illumine the people of God with the richest fruits of holiness, move it by their example, and extend it with hidden apostolic fruitfulness. For this reason, members of these institutes cannot be summoned to furnish assistance in the various pastoral ministries however much the need of the active apostolate urges it.
Source: Code of Canon Law (Vatican.va)