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One who blew from the wide end of the Shofar: 
If one blew from the wide end of the Shofar he does not fulfill his obligation.
 590/20; Michaber 590/9
 The reason: This is hinted to in the verse “Min Hameitzar Karasi Kah” that from the narrow [end] I call to G-d”. [Admur ibid; Yerushalmi] This however is merely an Asmachta and “Lashon Tzachus”. The reason mentioned in Rishonim [Ran; Ritva] however is because the verse states Vehavarta Shofar and Chazal received that this means the Shofar must be blown from the direction that it grew. [Chayeh Adam 140/5; M”B 590/36; Kaf Hachaim 590/72] Veztrauch Iyun why Admur did not record this reason.