In all of the Divine Services in LSB, we find this rubric after the salutation: "The presiding minister faces the altar. A brief silence may be observed. The presiding minister may raise his outstretched hands in the gesture of prayer while speaking or chanting the COLLECT OF THE DAY."
Two parts: both in the category of "may" rather than "shall" rubrics. Silence and then outstretched hands. The silence recognizes that the pastor's "Let us pray" is a bid. The congregation is thereby invited to lift its prayers in silence to the Lord. The collect by its very nature "collects" these individual intercessions and gives them voice. And the outstretched hands? Empty hands. Hands that are nothing but given to. Hands that are beggar's hands, awaiting the Lord's benefactions. Hands of a child outstretched to the parent to be lifted up, carried and loved. "Nothing in my hands I bring" we sing in one of popular hymns of the Western Church.
Sometimes the silence and the gesture can say more than any words can. These are "may" rubrics, but good ones to follow. They allow the congregation silence to gather its thoughts and the outstretched hands speak volumes by themselves. We are a people nothing but given to. We wait upon the Lord.