Amidah-Praying to Pray
The Talmud concludes that the words, “My Master, open You my lips,” recited at the beginning of the Amidah, are not considered an interruption between the blessing of Redemption and theAmidah, for inasmuch as the Rabbis decreed that it is to be recited, it is regarded as an extension of the Amidah. But then the Talmud’s statement should have been, “The rabbis decreed it as prayer.” We must therefore conclude that this phrase was not included in the original enactment by the Men of the Great Assembly, and when its recitation was decreed later, it was regarded as an extension of the prayer, rather than as part of the original enactment.
Thus, “My Master, open You my lips,” should be understood as a prayer for the ability to pray. The earlier generations had no need to pray for this, for surely their prayers were pure. Only later, when, “hearts diminished,” did they feel compelled to add a prayer that the prayers we are about to recite should be pure.
Hence, there are two aspects to prayer; the prayer itself, and a prayer for the ability to pray properly. (Kedushat Levi, Vaetchanan)