"For to keep"

1. Josh. 10: 18
     18 And Joshua said, Roll great stones upon the mouth of the cave, and set men by it for to keep them:
2. Acts 16: 4
     4 And as they went through the cities, they delivered them the ^adecrees for to keep, that were ordained of the apostles and elders which were at Jerusalem.
3. Mosiah 13: 25
     25 And it came to pass that after Abinadi had made an end of these sayings that he said unto them: Have ye ^ataught this people that they should observe to do all these things for to keep these commandments?