פירוש על ברכות 27:11

According to one interpretation, the Tefillah is here intended; otherwise it is contradicted by the passage quoted by Rab Sheshet from the Mishnah, which permits one to offer greeting between the sections of the Shema' — which is recited before the Tefillah. But R. Abba interprets the phrase "before he prays" quite generally.

On the Bamah was offered what should have been brought to the Temple. Similarly to greet a man before praying is to give him what is due to God.

To pay him honour instead of God.

I.e. translate "for as an idolatrous altar is he to be accounted" if honour is paid to him first.