[In 1634] war was declared against the Pequots, Capt. John Mason commanding the little army of ninety men, and Mr. Stone went with the men as their Chaplain. Capt. Mason, in reporting his victory, says:"It may not be amiss here also to remember Mr. Stone (the famous Teacher of the Church of Hartford), who was sent to preach and pray with those who went out in those Engagements against the Pequots. He lent his best Assistance and Counsel in the Management of those Designs, and the night in which the Engagement was, (in the morning of it), I say that Night he was with the Lord alone, wrestling with Him by Faith and Prayer, and surely his Prayers prevailed for a blessing; and in the very Time when our Israel was ingaging with the bloud-thirsty Pequots, he was in the Top of the Mount, and so held up his Hand, that Israel prevailed."It seems that when Mason's little army reached Saybrook, Lion Gardiner and Capt. John Underhill, who commanded a detachment of twenty men that the English company had caused to be sent from the Massachusetts colony for the defence and protection of the Saybrook settlement, both opposed the expedition. Each one had seen military service in the Netherlands, and looked upon an attack on the most warlike tribe in New England as a very hazardous undertaking for so small a band. Capt. Mason finally turned to Mr. Stone "and desired him that he would that Night commend their Case and Difficultyes to the Lord." The chaplain did so, and in the morning told Mason "that though he had formerly been against sailing to Naraganset and landing there, yet now he was fully satisfied to attend to it." This appears to have decided the matter, as "they agreed all with one accord" to go on.
Booth, Charles Edwin. One Branch of the Booth Family: Showing the Lines of Connection with One Hundred Massachusetts Bay Colonists. New York: Private Printing, 1910. (p. 215)
You can read detailed contemporary narratives about the Pequot war at my companion blog, My Ancestors in Books.