May 10

Of the new Obligatory Prayers that were later revealed, the long Obligatory Prayer should be said at those times when one feeleth himself in a prayerful mood. In truth, it hath been revealed in such wise that if it be recited to a rock, that rock would stir and speak forth; and if it be recited to a mountain, that mountain would move and flow. Well is it with the one who reciteth it and fulfilleth God's precepts. Whichever prayer is read will suffice. 

- Baha’u’llah  (Compilation on ‘The Importance of Obligatory Prayer and Fasting’, prepared by Research Department of the Universal House of Justice)