שמות פרק טו, כ ב וַיַסַע משֶה אֶת -י שְרָאֵל מ יַם-סוּף וַיֵצְאוּ אֶל-מ דְ בַר -שוּר וַיֵלְכוּ שְלשֶת-יָמ ים בַמ דְ בָר וְלֹא-מָצְאוּ מָי ם
The Gemara derives an allusion from this verse that the Torah is read on Shabbos, Monday and Thursday in order that three days should not pass without Torah, which is likened to water.
This limit of three days is actually a maximum time, meaning that we should not go without Torah reading for a period of more than three days. However if possible, we could read the Torah every day. This is similar to the concept that we have an established procedure to pray three times a day, yet the famous saying, “if only a person would pray all day.” Praying is considered חיי שעה, whereas Torah learning is considered חיי עולם. Thus, how much more so does this apply to Torah.
Therefore Rabbi Epstein says in addition to the established procedure to read the Torah on Monday and Thursday, it would be positively received to publicly read the Torah any day of the week. And this would not be considered a new decree, since we see that the Torah is read on a Fast day, whichever day of the week it occurs.
