Alma 2:26 - 2:30
Alma 2:26 And it came to pass that the people of Nephi took their tents, and departed out of the valley of Gideon towards their city, which was the city of Zarahemla.
Alma and the Nephite army quickly broke camp in the valley of Gideon started to return to Zarahemla.
Alma 2:27 And behold, as they were crossing the river Sidon, the Lamanites and the Amlicites, being as numerous almost, as it were, as the sands of the sea, came upon them to destroy them.
As they were crossing the Sidon River, the combined armies of the Lamanites and the Amlicites attached them. It seemed to the Nephites that their numbers were more than the sand on the sea shore.
Alma 2:28 Nevertheless, the Nephites being strengthened by the hand of the Lord, having prayed mightily to him that he would deliver them out of the hands of their enemies, therefore the Lord did hear their cries, and did strengthen them, and the Lamanites and the Amlicites did fall before them.
The Nephites were vastly out number and now prayed for greater strength to fight the Lamanites so they could preserve their country, their own lives and that of their families. The Lord did hear their prayers and did strengthen them so that the Lamanite army was now falling before them.
Alma 2:29 And it came to pass that Alma fought with Amlici with the sword, face to face; and they did contend mightily, one with another.
Alma and Amlici now faced each other and did fight with all the strength they each had.
Alma 2:30 And it came to pass that Alma, being a man of God, being exercised with much faith, cried, saying: O Lord, have mercy and spare my life, that I may be an instrument in thy hands to save and preserve this people.
However, Alma being a prophet and a man of God cried to the Lord that he might be preserved to save his people in this one on one fight with Amlici.