The content of their prayers is described in Alma 17:
’…they fasted much and prayed much that the Lord would grant unto them a portion of his Spirit to go with them, and abide with them, that they might be an instrument in the hands of God to bring, if it were possible, their brethren, the Lamanites to the knowledge of the truth, to the knowledge of the baseness of the traditions of their fathers, which were not correct.’ (Alma 17:9)