Isaiah 56:4-6

Amplified Bible

“To the eunuchs who keep My Sabbaths
And choose what pleases Me,
And hold firmly to My covenant,
⁵ 
To them I will give in My house and within My walls a memorial,
And a name better than that of sons and daughters;
I will give them an everlasting name which will not be cut off.

⁶ 
“Also the foreigners who join themselves to the Lord,
To minister to Him, and to love the name of the Lord,
To be His servants, everyone who keeps the Sabbath without profaning it
And holds fast to My covenant [by conscientious obedience];