It is customary to bless the children each Shabbat and on the holidays.
To bless a boy, a girl, or both, place your hands on the child’s head and say:

For a boy:
Y’sim-cha Eh-lo-him k’Ephra’im v’chi-M’nasheh.
May God inspire you to live in the tradition of Ephraim and Menasheh.

For a girl:
Y’si-meich Eh-lo-him k’Sarah, Rivka, Rachel, v’Lei-ah.
May God inspire you to live like Sarah, Rebekah, Rachel, and Leah.

For both boys and girls:
Y’va-reh-ch’cha Adonai v’yish-m’reh-cha. Ya-eir Adonai pa-nav ei-leh-cha vi-chu-neh-ka. Yisa Adonai pa-nav ei-leh-cha v’ya-seim l’cha sha-lom.

May God bless you and keep you. May God’s light shine upon you, and may God be gracious to you. May you feel God’s Presence within you always, and may you find peace.