VATICAN CITY - Pope Francis is entering the final busy days of Holy Week by acknowledging the exhaustion priests like him can feel, but urging them to keep emotionally close to their flock through life's joys and sorrows.

Francis celebrated Holy Thursday Mass hours before heading to Rome's main prison to wash the feet of inmates -- a pre-Easter ritual designed to show his willingness to serve others.

Francis said the rite shows how Jesus was willing to really get involved in the lives of his disciples, and said all priests must "wear the smell of their sheep" and not close themselves off in their sacristies out of exhaustion or indifference.

Francis said he thinks often about the weariness of priests "and I pray about it, often, especially when I am tired myself."