do not forbid

Spencer W. Kimball: If a person, not a member of the Church, is in the congregation, we do not forbid him partaking of it, but would properly advise that the sacrament is for the renewing of covenants. And, since he has not made the true covenant of baptism or temple covenant, he is exempt. However, his partaking of the sacrament if he is clean and worthy and devout would not bring upon him any condemnation as it would for those who have made solemn covenants and then have ignored or defied them.

(Book: "The Teachings of Spencer W. Kimball," p. 226)