Is there evidence other than that which jurists have used to infer the obligation of praying upon the Prophet (peace be upon him) in the last tashahhud of prayer?

No evidence has been found to necessitate invoking blessings upon the Prophet in the tashahhud other than the Prophet's own command. He said to someone who asked him, "How do we invoke blessings upon you?" "Say: 'Allahumma salli 'ala Muhammad' (O Allah, send blessings upon Muhammad)." Scholars have differed regarding the obligation of invoking blessings upon the Prophet, peace and blessings be upon him, after the final tashahhud in prayer. Abu Hanifa, Malik, and the majority of scholars hold that it is a sunnah (recommended), while Ash-Shafi'i and Ahmad hold that it is obligatory. Those who argue for its obligation cite the hadith of Abu Mas'ud Al-Ansari and others, and they believe that the command to invoke blessings implies obligation. The obligatory wording, according to them, is to say: "Allahumma salli 'ala Muhammad."