Pope Francis entered the final busy days of Holy Week by acknowledging the exhaustion that priests like himself can feel, but urging them to keep emotionally close to their flock through life's joys and sorrows.

In his Holy Thursday homily, Francis said he thinks often about the weariness of priests "and I pray about it, often, especially when I am tired myself." The 78-year-old pope, known for his near-workaholic ethic, lost most of one lung in his 20s due to an infection.

Francis urged the priests in the pews to take a rest, but to also embrace the "good and healthy tiredness" of being a good pastor.

"It is the exhaustion of the priest who wears the smell of his sheep, but also smiles the smile of a father rejoicing in his children or grandchildren," said Francis, who shuns vacations, often works seven days a week and rises daily at 4:30 a.m. to pray and meditate.

Holy Thursday, which this year falls on the 10th anniversary of the death of St. John Paul II, marks the start of a busy four days for Francis. On Friday, he performs the late night Via Crucis procession at Rome's Colosseum. On Saturday, he presides over the solemn Easter Vigil and a few hours later he celebrates Easter Sunday Mass.

Later Thursday, Francis heads to Rome's Rebibbia prison where he will wash the feet of a dozen inmates — a pre-Easter ritual designed to show his willingness to serve others. Francis has revolutionized the rite by performing it on women and non-Catholics as well, when Vatican rules call for it to be a male-only affair.

Half of those attending will be inmates from a nearby women's prison, including mothers with infants, Vatican Radio reported.

Francis has focused much attention on prison ministry, denouncing the death penalty as inhumane and calling life terms "hidden" death sentences.