A zav who experienced a seminal emission, and a niddah who emits semen, and a woman who had intercourse and saw niddah [blood] require immersion [in a mikveh]. But R’ Yehudah exempts [them].

The Morning Prayer [may be recited] until midday. R’ Yehudah says: Until four hours [into the day]. The Minchah Prayer [may be recited] until evening. R’ Yehudah says: Until plag haminchah. The Evening Prayer has no set [time]. And the Mussaf Prayer [may be recited] the entire day. R’ Yehudah says: Until seven hours [into the day].