Blessing of Rosaries (Shorter Rite)

To begin, the celebrant says:

Lord, show us your mercy and love.

All reply:
And grant us your salvation.

As circumstances suggest, the celebrant may begin with an explanation of the blessing. 
Someone reads a text of sacred Scripture, such as the following.

Lk 2:51b-52
Mary, his mother, kept all these things in her heart. And Jesus advanced in wisdom and age and favor before God and man.

or

Acts 1:14
All these devoted themselves with one accord to prayer, together with some women and Mary, the mother of Jesus, and his brothers.

With his hands outstretched, the celebrant says the prayer of blessing:

Blessed be our God and Father,
who has given us the mysteries of his Son
to be pondered with devotion
and celebrated with faith.
May he grant us, his faithful people,
that by praying the rosary we may,
with Mary, the Mother of Jesus,
seek to keep his joys, sorrows,
and glories in our minds and hearts.

We ask this through Christ our Lord.
R. Amen.

or

In memory of the mysteries
of the life, death, and resurrection of our Lord
and in honor of the Virgin Mary,
Mother of Christ and Mother of the Church,
may those who devoutly use this rosary
to pray be blessed,
in the name of the Father, and of the Son, and
of the Holy Spirit. 
R. Amen.