Shri Nathji used to say:
Not everything has been explained in the Ramayana. There was more in the Kewat episode. When Kewat asked Lord Rama to carry him across the Bhavsaagar in return for the services he had rendered him on earth, Lord Rama replied:
Had I not intended to take you across the waters of the bhavsaagar, I would never have taken a ride in your boat!
“Agar maine tumhe bhavsaagar se paar na karnaa hotaa to kabhi tumhaari naav men naa baith taa!”
Indeed, there were many boatmen in the area, and Lord Rama could have chosen any of them. The very fact that he chose Kewat, meant that he intended to give salvation to him. Blessed is the man who is chosen by God to serve Him, for the salvation of such a man is assured.