Prefatory 0
In plain words
Shankara, the teacher who in his grace gives knowledge of the Self: could he be anything other than that Self? And the one who now speaks this teaching in Tamil, dwelling in my heart as the Self: who could he be, if not that same Shankara?
Word for word
Could Shankara, the teacher who graciously imparts knowledge of the Self, be other than that Self? And he who, abiding in my heart as the Self, now speaks [it] in Tamil: who else is he, other than that very one?