In the Temple, the priests would bless the people. Today, they (Kohanim) still bless the people in the synagogue. In Israel, they do it every day. Outside of Israel, only on Holidays (Yom Tov) when everybody is in high spirits.
In the Temple, the priests were barefoot; today, they also take their shoes off for the blessing. If the priests have something unusual about their hands or feet, they should not bless the people who might be distracted by looking at them. But today, it does not apply because the priests wear socks, and their hands are covered with a tallith.
There is a prohibition in the Torah that one should not take a mother bird with its young. Instead, he should send away the mother bird. However, if he uses this as an argument in his prayer, saying that he, too, deserves mercy - the Talmud says his prayer text should be changed. That is because he is saying that the reason for this mitzvah is mercy on birds - but the real reason is unknown to people. Today, the prayer text is in the prayer books, and again this warning does not apply.
Art: Bird's nest by Franz Xaver Petter