Pope Francis reflected on in the importance of silence in his daily homily, noting that God's plan of salvation always includes moments of mystery and quiet.

"Silence is really the 'cloud' that covers the mystery of our relationship with the Lord, our holiness and our sins. We cannot explain this mystery, but where there is no silence in our lives, the mystery is lost, it goes away. Guard the mystery with silence!" said the Pope on Dec. 20.

The Pontiff considered today's gospel passage containing the story of the annunciation, in which Mary is "overshadowed" by the Holy Spirit in conceiving Jesus.

The mystery of God becoming man is carefully protected, he noted.

"This is what happened to the Virgin Mary when she received her son: the mystery of her virginal motherhood is covered. It covers all of her life, and she knows it."

"How many times did she keep quiet and how many times did she not say how she felt in order to guard the mystery of her relationship with her son," Pope Francis reflected.

Particularly when Mary stood at the foot of the Cross, "the gospel doesn't tell us anything - if she said a word or not...she was quiet, but in her heart how many things was she saying to the Lord!"

"Our Lady was human!" insisted the Pontiff, so perhaps she wanted to say to God, "'you told me that he would be great, you told me that you would give him the throne of David his father, who would reign forever and now I see him there!'"

"But she, with silence, covered the mystery that she did not understand and with this silence allowed the mystery to be able to grow and flower in hope," he said.

Just as Mary lived the power of silence, every Christian "knows the mysterious work of the Lord in our hearts, in our souls."

Silence "helps us to discover our mystery: our mystery of encountering the Lord, our mystery of walking through life with the Lord," encouraged Pope Francis.

The Pontiff then concluded his homily in the chapel of the Saint Martha guesthouse by praying that "the Lord would give us the grace to love silence, to seek it and to have a heart guarded by the 'cloud' of silence."