Related על ברכות 3:1

The grooms and all [others] who are involved in [other] Mitzvot (commandments) are exempt from reading [the] Shema and from [the Amidah] prayer and from Tefillin (phylacteries), as it is said, “… when you sit in your house”, (Deuteronomy 6:7) which excludes grooms, “and when you walk on the way”, (Deuteronomy 6:7) which excludes those who are involved in mitzvot.