There is a certain tension between the importance of making tefilla responsive to the individual’s needs and circumstances[1] and the importance of preserving the set framework of tefilla, as formulated by the Anshei K’nesset HaGedola.
The gemara[2] and poskim[3] mediate this tension through the following balanced approach:
During the first three and last three berachot of Shemoneh Esrei, in which one praises and thanks HaShem, we make no requests.[4] During the middle berachot, which are comprised of fixed requests, one may add private requests that pertain to the given beracha to address a present need (and not a future one, such as “Please may I not get sick”).[5] Some say that personal requests should be formulated in the singular, since using the plural, which is the format of the set tefilla, gives the impression that the tefilla itself is being altered.[6]
The last of the middle berachot, Shomei’a Tefilla, is the most general of all the petitionary berachot and thus most easily lends itself to personal requests. Therefore, any request may be added at that point, even those that relate to potential or future needs, and it may be formulated in the plural.[7] However, even in this case, some poskim place limitations:
1. The personal insertion should not be too long.[8]
2. A supplementary prayer should not turn into a permanent part of the Shemoneh Esrei text, as it is an affront to the Anshei K’nesset HaGedola, especially if the voluntary prayer is printed in a siddur.[9] Others, however, are not troubled by this possible insult as long as the text of the supplementary prayer comes from a recognized source, such as the Zohar.[10] Certainly, in the case of an acute and persistent need, one may continue praying for it on a regular basis.
The proper place to insert the addition is in the middle of the beracha,[11] preferably just prior to the last phrase preceding the beracha’s ending, e.g., where Aneinu is inserted on fast days.
The simplest place to insert personal petitions, however, is after the conclusion of the actual Shemoneh Esrei (before Elokai Netzor), either before or after reciting “Yiheyu l’ratzon…,”[12] where none of the above reservations apply. There is a range of opinions whether it is best to use this safer system, or whether one should insert the request where permitted at the earlier, central part of tefilla.
There is no obligation to make any additions to Shemoneh Esrei. Moreover, it is perfectly appropriate for one to meditate on his private needs at the appropriate parts of the tefilla, without adding any words. Nevertheless, those who would benefit from expressing what is on their minds are encouraged to take advantage of this halachic opportunity. This also demonstrates that halacha at times has certain built-in flexibility and individuality, and is not as rigid and impersonal as some claim.