Is there a hadith regarding fasting three days before the Prayer for Rain (Salat Al-Istisqa)?

There is no prophetic hadith that commands fasting before the prayer for rain (Salat al-Istisqa), but many jurists have deemed it recommended, inferring this from the general implications of hadiths indicating the answering of a fasting person's prayer. This is also because fasting makes the heart more submissive and more conducive to attentiveness during supplication. Some jurists, however, have held that it is not prescribed for the Imam to command people to fast in this manner.