There are various parts in our Service which originally seem to have
formed a substitute, under certain circumstances, for a section of the
Service or for the whole of it, but were subsequently, when the
circumstances altered, embodied as an integral part of the Service in
addition to the sections which they had replaced.
In the Morning Service there is in the section called ברכות השחר a
prayer beginning לעולם יהא אדם and concluding לעיניכם אמר יי. This
prayer, preceded by an exhortation to be God-fearing in secret—when
persecution prevented public worship of God—contains an expression of
pride in our history, and of gratitude to God that we have the
privilege to proclaim the Unity of God in the words, “Hear, O Israel,”
&c., and a petition for the fulfilment of the Messianic prophecies.
In the Maaribh the part beginning ברוך יי לעולם and ending על כל
מעשיו was originally a substitute for the Amidah, and the conclusion
of the Evening Service for those who considered the tefillah in the
evening optional. Similarly, on Friday evening the contracted tefillah
was originally a substitute for the tefillah for those who came late.
In both these and similar cases the substitute and its original have
been retained as integral parts of the Service.