In the Gemara Berachot, the commentary of Tosafot examines the regulations concerning blessings where the Sages established a concise format. The discussion centers on the principle that in a place where it was ordained to be brief, one does not have the license to extend the prayer. This category of short blessings includes those recited over the consumption of fruit as well as those recited before performing a commandment.
The specific examples provided for blessings over fruit include the formulas recited for the fruit of the tree and the fruit of the ground. These are defined by their brevity; they consist of a single opening and do not conclude with a formal signature. This same structure applies to the blessings over commandments, such as the blessing for taking the palm branch or the blessing for dwelling in a ritual booth. In all these instances, the blessing is intended to be direct and short.
Because these particular blessings were established without a concluding signature, the law remains firm that one should not attempt to lengthen them. The halachic requirement is to maintain the established brevity, ensuring that no concluding signature is added to a blessing that the Sages designated as short.