Which preposition to use with decode

to Occurrences 2%

At the end of a twenty-mile walk on a day of suffocating heat, Duchemin plodded wearily into the Hôtel du Commerce, engaged a room for the night, and was given a telegram from London which rewarded decoding to some such effect as this: "MONK AMERICAN INDEPENDENT MEANS GOOD REPUTE

Which preposition to use with  decode