Some Thoughts on Salla ‘Ala (‘Pray Upon’)

What might the Arabic صلى على ‘pray upon’ have signified at the time of composition of the Quran? In S 33:43 we read: He is the one who prays for you and his angels to bring you out of the darknesses into the light and he was merciful to the believers.

In S 33:56 we read: Allah and his angels pray for the prophet. Those who have believed, pray for him and salute him.

Did the author want the reader to understand that Allah would be standing on its boss? I suspect that a Syriac idiom, tzali ‘al, lies behind this expression. This can mean, according to my understanding, ‘pray for’ or ‘pray over’

In the Peshitta we read (Hebrews 13:18): ܨܠܘ ܥܠܝܢ ܬܟܝܠܝܢܢ ܓܝܪ ܕܬܐܪܬܐ ܛܒܬܐ ܐܝܬ ܠܢ ܕܒܟܠܡܕܡ ܨܒܝܢܢ ܕܫܦܝܪ ܢܬܕܒܪ ܀ tzalaw ‘alayn, pray for us. And in James 5:14 ܘܐܢ ܟܪܝܗ ܢܩܪܐ ܠܩܫܝܫܐ ܕܥܕܬܐ ܘܢܨܠܘܢ ܥܠܘܗܝ ܘܢܡܫܚܘܢܗ ܡܫܚܐ ܒܫܡܗ ܕܡܪܢ ܀ wa-ntzalon ‘alaw, and they will pray over him. Peshitta New Testament

So I understand that the author of the Quran meant ‘pray for’.