(condensed from Ein Ayah, Shabbat 2:268)

Gemara: When Rabbi Shimon and his son prayed, they wore their clothes and prayed and then removed their clothes again so that they would not get worn out.

Ein Ayah: Prayer is related to emotions, and, therefore, it has a connection to social life. Therefore, specifically at the time of prayer did Rabbi Shimon and his son allow themselves to use something that was man-made. This required something connected to human interaction, as imperfect as that is, as during prayer it is necessary to address the needs of the present.

In truth, one can be on the highest level and still find advantage in social life, and this can fit in with the highest and holiest intellectual level. There were times that even after prayer, Rabbi Shimon and his son remained in a situation that they could have remained connected to society. This was as long as the light of divine emotion that is related to the intellect reached the highest possible level, so that it properly connected to all elements of life. However, they reserved this rare state for the times that it was most needed, which was the time of prayer. At that time, it was easier to preserve the connection between the intellect, emotion, and society because that was their focus at the time of prayer.

Therefore, on a regular basis, they would remove their clothes (i.e., their connection to society), so that they not get worn out. At the time of their learning, when they had no natural need to be connected to society, it would have been difficult for them to preserve this connection.