1 Chronicles 5:1,2

Now the sons of Reuben, the firstborn of Israel.

Reuben’s rights transferred to Joseph

This incident is worth dwelling upon, only because it elucidates a special phase of the Divine government. God is not bound by arbitrary laws. Primogeniture can be changed in the court of heaven. Conduct is the only absolute guarantee of real and enduring primogeniture. “Once in grace, always in grace,” may be a glorious truth, but everything depends upon what is meant by being “in grace.” They are not all Israel that are called Israel. We can only prove that we were once in grace by continually living in grace. Any vital breach in the continuance will throw discredit upon the supposed reality of the origin. (J. Parker, D. D.)