Thou art our sister, i.e. our near kinswoman; distance of place shall not alienate our affections from thee, but we shall still own thee as our sister, and, as far as we can, be ready to perform all the duties of brethren to thee.
Related Commentaries of Genesis 24:60
Genesis 24:60
60 And they blessed Rebekah, and said unto her, Thou art our sister, be thou the mother of thousands of millions, and let thy seed possess the gate of those which hate them.