Answered by Shaykh Faraz Rabbani
In the final raka, how important is it to recite: 1. Salat Alan-nabi 2. A short prayer and is a short prayer obligatory before the Salam or can one recite Salam directly after Salat Alan-Nabi?
Walaikum assalam wa rahmatullah,
Both sending blessings upon the Prophet (peace and blessings be upon him) and making a short supplication are confirmed Prophetic sunnas in the final rakat, before giving the closing salams. [ Shurunbulali, Maraqi al-Falah ] As such, they should not be left, even when making up missed prayers. [Shaykh Adib Kallas]
Leaving either one without a strong excuse is blameworthy, and making it a habit to do so could be sinful. [ Ibn Abidin, Radd al-Muhtar ] However, doing so does not invalidate one’s prayer.
And Allah alone gives success.
Faraz Rabbani