Unveiling the Significance of Supplicating Blessings upon the Prophet Muhammad
THE MEANING OF ALLĀHUMMA SALLI ALAA MUḤAMMADIN
Shaykh Ibn Uthaymīn (may ALLĀH have mercy on him) said:
What is the meaning of supplicating blessings upon the Prophet? That is, what is the meaning of the saying of one who says: Allāhumma salli alaa Muḥammad? Most people read this supplication or beseech ALLĀH with it without understanding its meaning. This is a mistake. It is obligatory for you to know the meaning of everything you say or supplicate with so that you will not supplicate with what contains sin.
Therefore, your saying “Allāhumma Salli alaa Muḥammadin” means, ‘O ALLĀH praise him in the highest assembly’. And the meaning of ‘praise him’ is ‘mention him with praiseworthy attributes’. And the highest assembly refers to the angels. So when you say, “Allāhumma Salli alaa Muḥammadin” is as if you are saying, ‘O Lord, describe him with praiseworthy attributes and mention him before the Angels so that they will increase in their love for him and his reward will increase with it’. This is the meaning of Allāhumma Salli alaa Muḥammadin.
{Sharḥ Riyadhus-Saliḥīn, 5/517-518}