The Gemara considers the possibility that one might be mislead into thinking that Birkas HaMazon is time-related because of a verse mentioning the times of eating. Why would a verse discussing times of eating and not discussing the times of benching lead one to think that bentching is time-related?
Mr. Mordechai Perlman, Jerusalem, Israel
Since the meal times are fixed for the evening and the morning, it follows that in practice the times at which one says Birkas ha'Mazon are also fixed for evening and morning. Since the fixed times for eating automatically lead to fixed times of Birkas ha'Mazon, one might have been mislead into thinking that the Mitzvah of Birkas ha'Mazon is time-related.