Jahr is audible recitation; ikhfat is recitation with a lowered voice. A well-known juristic distinction treats audibility to another as jahr and audibility to oneself as the boundary of ikhfat. Mere lip or tongue motion without recitation is a separate issue.
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Defining Jahr and Ikhfat
Rules of Audible and Quiet Recitation in Salah
Jahr is audible recitation; ikhfat is recitation with a lowered voice. A well-known juristic distinction treats audibility to another as jahr and audibility to oneself as the boundary of ikhfat. Mere lip or tongue motion without recitation is a separate issue.