John: There is no specific scripture re the “red heifer” as it relates to the return of Jesus Christ. The red heifer is a part of the Old Testament Jewish sacrifice which will be re-instated prior to Christ’s return. Jesus told His followers that He would come again to establish His earthly kingdom. There are set times in scripture so that God’s eternal plan can unfold. Indeed Christ lives within us as true believers and we are part of His spiritual kingdom, but He has a plan for this world, that will ensure justice and righteousness is carried out. If this were not so, then the injustices of our world would never end.
There is so much to discuss re “end times” and if our theology is too far apart, then we can only get so far. In closing, I don’t refer to myself as a dispensationalist; however, it is clear to me that the Bible is a progressive book both historically and spiritually. Jesus told us to pay attention “to the times and the seasons.” When the Word of God is broken down it is easier to understand, but I would never say that we have the ability to make it an exact science of study.
Have a great day! KingsKid