Shulchan Arukh Orach Chayim · Siman 104

English

To Not Interrupt In The [Middle Of The Amidah] Prayer. Containing 8 S'ifim: One may not interrupt during one's prayer [i.e. Amidah]. And even if a Jewish king is inquiring about one's well-being, one may not respond to him. But [regarding responding to] a king of the nations of the world, if one is able to shorten [one's prayer], meaning that one would say the beginning of the blessing and its end before the [king] reaches one, one should shorten it. Or if [one's on the road and] one is able to veer off the road, [then] one should veer off, but one may not interrupt by talking. And if it's impossible for one [to do so], one may interrupt.

English

If one was praying on the road and an animal or a wagon approaches before one, one should veer from the road and not interrupt [by talking]. But for another matter, one should not go out from one's place until one finishes one's prayer, unless one is up to the supplications that are after the [Amidah] prayer.

English

And even [if] a snake is coiled around one's heel, one should not interrupt, (but one may move to a different place so that the snake falls off one's leg) (the Ri at the beginning of Chapter "Ain Omdin" [Berachot 30b:14]). But [regarding] a scorpion - one interrupts, because it is more prone to do harm; and so too a snake, if one sees that it is angry and ready to do harm, one interrupts.

English

If one saw an ox approaching one, one interrupts [one's prayer]. For we distance from a regular ox (i.e. one that is not accustomed to do harm) 50 cubits, and from a forewarned ox (i.e., that is accustomed to do harm] as far as one can see. And if oxen in that place are known not to do harm, one does not interrupt.

English

In any circumstance where one interrupted, if one delayed long enough to finish all of it [i.e. the Amidah prayer], one must return to the beginning; and if not, then one returns to the beginning of the blessing that one interrupted. And if one interrupted in one of the first three [blessings], one returns to the beginning; and if it was in one of the latter ones [i.e. three blessings], one returns to [the blessing of] "R'tzei".

English

This [thing] that we said: "that if one delayed long enough to finish all of it [i.e. the Amidah prayer]", we calculate [that time] based on the speed of] the one reading (i.e. praying). If one conversed during the [Amidah] prayer, the law regarding the matter of returning [to an earlier part of the prayer] is like the law regarding interruptions mentioned in this siman.

English

One may not interrupt [the Amidah], not for [the responses in the] Kaddish and not for Kedusha. Rather, one should be silent and focus on what the prayer leader is saying and it will be [considered] like one is answering. (If one is standing during one's [Amidah] prayer and they called that person up [for an aliyah] to the Torah scroll, one does not interrupt.) (Rashb"a in Siman 185)

English

After one finished the eighteen blessings [of the Amidah], [but] before [one said] "Elokai, netzor", one may answer Kedusha, Kaddish, and Barchu. [And see below in Siman 122].