Isaiah 56:2-6

2Blessed is the man that doeth this, and the son of man that layeth hold on it; that keepeth the sabbath from polluting it, and keepeth his hand from doing any evil.

3Neither let the son of the stranger, that hath joined himself to Yhwh, speak, saying, Yhwh hath utterly separated me from his people: neither let the eunuch say, Behold, I am a dry tree. 4For thus saith Yhwh unto the eunuchs that keep my sabbaths, and choose the things that please me, and take hold of my covenant; 5Even unto them will I give in mine house and within my walls a place and a name better than of sons and of daughters: I will give them an everlasting name, that shall not be cut off. 6Also the sons of the stranger, that join themselves to Yhwh, to serve him, and to love the name of Yhwh, to be his servants, every one that keepeth the sabbath from polluting it, and taketh hold of my covenant;